gene_symbol	uniprot_acc	class	ground_truth_verdict	ground_truth_signal	ground_truth_reason	rationale	hgnc_id	hgnc_symbol	ncbi_gene_id	ensembl_gene	ensembl_canonical_protein	n_db_votes	sonnet_verdict	sonnet_reason
CD19	P15391	validated_positive	yes	likely_accessible	classical_surface_receptor	Approved CAR-T + ADC; classical B-cell surface marker	HGNC:1633	CD19	930	ENSG00000177455	ENSP00000313419.4	4	yes	classical_surface_receptor
FOLR1	P15328	validated_positive	yes	likely_accessible	gpi_anchored	Approved Mirvetuximab (ELAHERE); GPI-anchored on outer leaflet	HGNC:3791	FOLR1	2348	ENSG00000110195	ENSP00000308137.4	4	yes	gpi_anchored
MUC1	P15941	disagreement_rich_positive	yes	likely_accessible	classical_surface_receptor	TROP-2-adjacent validated tumor antigen; large mucin ECD; multiple antibody programs	HGNC:7508	MUC1	4582	ENSG00000185499	ENSP00000338983.5	4	yes	classical_surface_receptor
CD74	P04233	disagreement_rich_positive	yes	likely_accessible	classical_surface_receptor	Invariant chain on B/dendritic cell surface; clinical-stage Milatuzumab ADC	HGNC:1697	CD74	972	ENSG00000019582	ENSP00000009530.7	4	yes	classical_surface_receptor
PMEL	P40967	dual_localization_borderline	contextual	possibly_accessible	dual_localization	Single-pass type I TM glycoprotein with a large extracellular domain. Canonical residence is melanosomal (lysosome-related organelle), but the protein transits the PM during melanosome biogenesis and surface biotinylation / flow cytometry / HMB-45 IHC detect a minority PM pool on melanocytes and melanoma cells — gene-specific evidence for `contextual / dual_localization`. The separate tebentafusp / gp100·HLA pMHC story does not affect this verdict either way (pMHC is not credited for protein-body surface accessibility, but PMEL has its own documented PM transit independent of MHC presentation).	HGNC:10880	PMEL	6490	ENSG00000185664	ENSP00000402758.2	2	contextual	dual_localization
SLC34A2	O95436	disagreement_rich_positive	yes	likely_accessible	multipass_with_exposed_loops	Apical phosphate transporter; clinical Lifastuzumab vedotin ADC	HGNC:11020	SLC34A2	10568	ENSG00000157765	ENSP00000371483.3	4	yes	multipass_with_exposed_loops
PRAME	P78395	pmhc_only_negative	no	unlikely	pmhc_only_intracellular	Cancer-testis antigen; intracellular at baseline. Clinical T-cell engagers (brenetafusp / IMC-F106C) target the HLA-A*02-restricted peptide, but the protein body is not surface — `no` / `pmhc_only_intracellular`.	HGNC:9336	PRAME	23532	ENSG00000185686	ENSP00000381726.1	1	no	pmhc_only_intracellular
CALR	P27797	induced_borderline	contextual	possibly_accessible	cell_state_induced	ER-resident at baseline; reaches outer leaflet during immunogenic cell death	HGNC:1455	CALR	811	ENSG00000179218	ENSP00000320866.4	3	contextual	cell_state_induced
HSPA1A	P0DMV8	induced_borderline	contextual	possibly_accessible	cell_state_induced	Cytoplasmic at baseline; tumor-stress-induced surface presentation	HGNC:5232	HSPA1A	3303	ENSG00000204389	ENSP00000364802.5	0	contextual	cell_state_induced
HSPA5	P11021	induced_borderline	contextual	possibly_accessible	cell_state_induced	ER chaperone at baseline; ER-stress/oncogenic-state translocation to outer leaflet	HGNC:5238	HSPA5	3309	ENSG00000044574	ENSP00000324173.6	1	contextual	cell_state_induced
KRAS	P01116	wrong_side_negative	no	unlikely	inner_leaflet_anchored	"Membrane-anchored on the cytoplasmic face; tests ""membrane = surface"" trap"	HGNC:6407	KRAS	3845	ENSG00000133703	ENSP00000256078.5	1	no	inner_leaflet_anchored
LAMP1	P11279	induced_borderline	contextual	possibly_accessible	lysosomal_exocytosis	Classical lysosomal membrane glycoprotein; reaches plasma membrane via lysosomal exocytosis (CD107a degranulation marker on NK / cytotoxic T cells, surface staining on metastatic tumor cells). Conditional surfacing puts it in the contextual class.	HGNC:6499	LAMP1	3916	ENSG00000185896	ENSP00000333298.4	2	contextual	lysosomal_exocytosis
ABCB9	Q9NP78	wrong_compartment_negative	no	unlikely	endomembrane_resident	Polytopic TM but lysosomal; TM topology does not imply PM accessibility	HGNC:50	ABCB9	23457	ENSG00000150967	ENSP00000280560.8	1	contextual	lysosomal_exocytosis
APPL1	Q9UKG1	opencell_vesicle_negative	no	unlikely	endomembrane_resident	Imaged-confirmed signaling endosome; M1 false positive	HGNC:24035	APPL1	26060	ENSG00000157500	ENSP00000288266.3	1	no	cytoplasmic
ATG9A	Q7Z3C6	wrong_compartment_negative	no	unlikely	endomembrane_resident	Cycles between Golgi/endosomes/autophagosomal precursors; multi-pass TM but never PM in steady state	HGNC:22408	ATG9A	79065	ENSG00000198925	ENSP00000355173.4	2	no	endomembrane_resident
TGOLN2	O43493	induced_borderline	contextual	possibly_accessible	dual_localization	TGN46 — **cycles continuously between TGN and PM** via the secretory recycling pathway; canonical marker for the TGN-PM trafficking cycle. Transient but routine surface presence.	HGNC:15450	TGOLN2	10618	ENSG00000152291	ENSP00000366603.3	2	no	endomembrane_resident
STEAP1	Q9UHE8	disagreement_rich_positive	yes	possibly_accessible	multipass_with_exposed_loops	TCR-T + bispecific: GSK4427296 TCR-T + AMG509 bispecific. 6-pass TM with small ECLs — also tests minimal_ectoloops case	HGNC:11378	STEAP1	26872	ENSG00000164647	ENSP00000297205.2	0	yes	multipass_with_exposed_loops
KLK2	P20151	disagreement_rich_positive	contextual	possibly_accessible	tissue_restricted_surface	KLK2 (hK2) — kallikrein-family secreted serine protease with no TM/GPI of its own. Surface accessibility is real but context-dependent: documented surface association on prostate epithelium and stable deposition on the sperm plasma membrane during seminal transit, plus PSMA-axis prostate-cell-surface co-targeting in clinical programs. Web-enabled triage runs across multiple models converge on contextual, never yes — the surface pool is tissue/cell-type restricted, not a canonical extracellular-face receptor.	HGNC:6363	KLK2	3817	ENSG00000167751	ENSP00000313581.2	0	no	secreted_only
CLDN6	P56747	disagreement_rich_positive	yes	likely_accessible	multipass_with_exposed_loops	CAR-T + ADC + bispecific: BNT211 CAR-T (BioNTech), AMG794 bispecific, multiple ADCs. Tight-junction claudin	HGNC:2048	CLDN6	9074	ENSG00000184697	ENSP00000328674.4	2	contextual	cell_state_induced
GPRC5D	Q9NZD1	disagreement_rich_positive	yes	likely_accessible	multipass_with_exposed_loops	approved bispecific + CAR-T: Talquetamab approved 2023 (multiple myeloma); orphan GPCR	HGNC:13310	GPRC5D	55507	ENSG00000111291	ENSP00000228887.1	2	yes	multipass_with_exposed_loops
GUCY2C	P25092	disagreement_rich_positive	yes	likely_accessible	classical_surface_receptor	approved bispecific + ADC: M9140 ADC; multiple approved/clinical programs	HGNC:4688	GUCY2C	2984	ENSG00000070019	ENSP00000261170.3	2	yes	classical_surface_receptor
PSCA	O43653	disagreement_rich_positive	yes	likely_accessible	gpi_anchored	clinical CAR-T + ADC: Multiple PSCA programs; GPI-anchored	HGNC:9500	PSCA	8000	ENSG00000167653	ENSP00000301258.4	2	yes	gpi_anchored
SEZ6	Q53EL9	disagreement_rich_positive	yes	likely_accessible	classical_surface_receptor	clinical ADC: ABBV-011 ADC (AbbVie SCLC)	HGNC:15955	SEZ6	124925	ENSG00000063015	ENSP00000312942.11	2	contextual	dual_localization
FZD7	O75084	disagreement_rich_positive	yes	likely_accessible	multipass_with_exposed_loops	clinical mAb: Vantictumab (OMP-18R5, Ipsen/OncoMed); 7TM Wnt receptor	HGNC:4045	FZD7	8324	ENSG00000155760	ENSP00000286201.1	2	yes	multipass_with_exposed_loops
LGR5	O75473	disagreement_rich_positive	yes	likely_accessible	multipass_with_exposed_loops	clinical ADC: Multiple Wnt-receptor ADC programs	HGNC:4504	LGR5	8549	ENSG00000139292	ENSP00000266674.4	2	yes	multipass_with_exposed_loops
EFNA4	P52798	disagreement_rich_positive	yes	likely_accessible	gpi_anchored	clinical ADC: PF-06647263 ADC	HGNC:3224	EFNA4	1945	ENSG00000243364	ENSP00000352789.4	2	yes	gpi_anchored
EREG	O14944	disagreement_rich_positive	contextual	possibly_accessible	dual_localization	Epiregulin — EGF-family ligand. TM precursor transits PM transiently before ADAM/MMP shedding; dominant detected and biologically active form is the soluble shed ligand. Clinical anti-epiregulin mAb programs exist but target the shed soluble pool.	HGNC:3443	EREG	2069	ENSG00000124882	ENSP00000244869.2	2	contextual	dual_localization
ROS1	P08922	disagreement_rich_positive	yes	likely_accessible	classical_surface_receptor	approved TKI + clinical ADC: Crizotinib/lorlatinib approved (small molecule); ADC programs in development	HGNC:10261	ROS1	6098	ENSG00000047936	ENSP00000357494.3	2	yes	classical_surface_receptor
DLL3	Q9NYJ7	disagreement_rich_positive	yes	likely_accessible	classical_surface_receptor	approved bispecific: Tarlatamab/Imdelltra approved 2024 SCLC	HGNC:2909	DLL3	10683	ENSG00000090932	ENSP00000205143.3	3	yes	classical_surface_receptor
ROR1	Q01973	disagreement_rich_positive	yes	likely_accessible	classical_surface_receptor	clinical CAR-T + ADC: Cirmtuzumab, Zilovertamab vedotin, Lyell CAR-T	HGNC:10256	ROR1	4919	ENSG00000185483	ENSP00000360120.1	3	yes	classical_surface_receptor
ROR2	Q01974	disagreement_rich_positive	yes	likely_accessible	classical_surface_receptor	clinical ADC: BA3021 conditionally-active ADC (BioAtla)	HGNC:10257	ROR2	4920	ENSG00000169071	ENSP00000364860.3	3	yes	classical_surface_receptor
CCR8	P51685	disagreement_rich_positive	yes	likely_accessible	multipass_with_exposed_loops	clinical mAb: Multiple anti-CCR8 mAb programs (Treg depletion)	HGNC:1609	CCR8	1237	ENSG00000179934	ENSP00000326432.4	3	yes	multipass_with_exposed_loops
EPHB4	P54760	disagreement_rich_positive	yes	likely_accessible	classical_surface_receptor	clinical mAb: Soluble EphB4 fusion programs	HGNC:3395	EPHB4	2050	ENSG00000196411	ENSP00000350896.3	3	yes	classical_surface_receptor
FLT3	P36888	disagreement_rich_positive	yes	likely_accessible	classical_surface_receptor	clinical ADC + CAR-T: AMG553 CAR-T, FLT3xCD3 bispecifics	HGNC:3765	FLT3	2322	ENSG00000122025	ENSP00000241453.7	3	yes	classical_surface_receptor
GFRA1	P56159	disagreement_rich_positive	yes	likely_accessible	gpi_anchored	clinical ADC: Multiple GFRalpha-1 ADC programs	HGNC:4243	GFRA1	2674	ENSG00000151892	ENSP00000347591.6	3	yes	gpi_anchored
GPNMB	Q14956	disagreement_rich_positive	yes	likely_accessible	classical_surface_receptor	clinical ADC: Glembatumumab vedotin (Celldex)	HGNC:4462	GPNMB	10457	ENSG00000136235	ENSP00000258733.5	3	yes	classical_surface_receptor
FZD10	Q9ULW2	disagreement_rich_positive	yes	likely_accessible	multipass_with_exposed_loops	clinical mAb: OTSA101-DTPA (radioimmunoconjugate)	HGNC:4039	FZD10	11211	ENSG00000111432	ENSP00000229030.4	3	yes	multipass_with_exposed_loops
ADORA3	P0DMS8	gpcr_extracellular_pocket	yes	likely_accessible	multipass_with_exposed_loops	clinical small molecule: Adenosine A3 receptor; multiple clinical programs	HGNC:268	ADORA3	140	ENSG00000282608	ENSP00000241356.4	1	yes	multipass_with_exposed_loops
GIPR	P48546	gpcr_extracellular_pocket	yes	likely_accessible	multipass_with_exposed_loops	approved peptide drug: Tirzepatide (GIP/GLP-1 dual agonist) approved	HGNC:4271	GIPR	2696	ENSG00000010310	ENSP00000263281.3	2	yes	multipass_with_exposed_loops
GCGR	P47871	gpcr_extracellular_pocket	yes	likely_accessible	multipass_with_exposed_loops	clinical peptide drug: Multiple glucagon receptor programs	HGNC:4192	GCGR	2642	ENSG00000215644	ENSP00000383558.3	2	yes	multipass_with_exposed_loops
HTR2C	P28335	gpcr_extracellular_pocket	yes	likely_accessible	multipass_with_exposed_loops	approved small molecule: Lorcaserin (was approved); 7TM serotonin receptor	HGNC:5295	HTR2C	3358	ENSG00000147246	ENSP00000276198.1	2	yes	multipass_with_exposed_loops
MC1R	Q01726	gpcr_extracellular_pocket	yes	likely_accessible	multipass_with_exposed_loops	approved peptide: Afamelanotide (Scenesse) approved; melanocortin	HGNC:6929	MC1R	4157	ENSG00000258839	ENSP00000451605.1	2	yes	multipass_with_exposed_loops
GPBAR1	Q8TDU6	gpcr_extracellular_pocket	yes	likely_accessible	multipass_with_exposed_loops	clinical small molecule: Bile acid receptor TGR5; multiple programs	HGNC:19680	GPBAR1	151306	ENSG00000179921	ENSP00000430698.1	2	yes	multipass_with_exposed_loops
BDKRB1	P46663	gpcr_extracellular_pocket	yes	likely_accessible	multipass_with_exposed_loops	clinical small molecule: Bradykinin B1 receptor; multiple programs	HGNC:1029	BDKRB1	623	ENSG00000100739	ENSP00000216629.6	2	yes	multipass_with_exposed_loops
HRH2	P25021	gpcr_extracellular_pocket	yes	likely_accessible	multipass_with_exposed_loops	approved small molecule: H2 receptor (ranitidine/famotidine class)	HGNC:5183	HRH2	3274	ENSG00000113749	ENSP00000366506.2	2	yes	multipass_with_exposed_loops
NPY5R	Q15761	gpcr_extracellular_pocket	yes	likely_accessible	multipass_with_exposed_loops	clinical small molecule: Neuropeptide Y receptor 5; obesity programs	HGNC:7958	NPY5R	4889	ENSG00000164129	ENSP00000339377.3	2	yes	multipass_with_exposed_loops
GRM4	Q14833	gpcr_extracellular_pocket	yes	likely_accessible	multipass_with_exposed_loops	clinical small molecule: Metabotropic glutamate receptor 4; CNS programs	HGNC:4596	GRM4	2914	ENSG00000124493	ENSP00000363292.3	2	yes	multipass_with_exposed_loops
AVPR1A	P37288	gpcr_extracellular_pocket	yes	likely_accessible	multipass_with_exposed_loops	clinical small molecule: Vasopressin V1A receptor; conivaptan family	HGNC:895	AVPR1A	552	ENSG00000166148	ENSP00000299178.3	2	yes	multipass_with_exposed_loops
SRC	P12931	wrong_side_borderline	contextual	possibly_accessible	cell_state_induced	Proto-oncogene tyrosine kinase; canonically myristoylated/palmitoylated to inner leaflet (cytoplasmic face). Ecto-SRC has been reported on cancer cell surfaces (melanoma, other tumors) — borderline conditional/pathological surfacing. M1 votes 3/6.	HGNC:11283	SRC	6714	ENSG00000197122	ENSP00000350941.5	2	no	inner_leaflet_anchored
RHOA	P61586	wrong_side_negative	no	unlikely	inner_leaflet_anchored	Rho GTPase; geranylgeranylated to inner leaflet. Cytoplasmic signaling.	HGNC:667	RHOA	387	ENSG00000067560	ENSP00000400175.1	2	no	inner_leaflet_anchored
GNAQ	P50148	wrong_side_negative	no	unlikely	inner_leaflet_anchored	Heterotrimeric G-alpha-q; lipidated cytoplasmic-side anchor.	HGNC:4390	GNAQ	2776	ENSG00000156052	ENSP00000286548.4	2	no	inner_leaflet_anchored
GNB1	P62873	wrong_side_negative	no	unlikely	inner_leaflet_anchored	G-protein beta-1 subunit; peripheral on inner leaflet via Gγ prenylation.	HGNC:4396	GNB1	2782	ENSG00000078369	ENSP00000367872.3	2	no	inner_leaflet_anchored
LYN	P07948	wrong_side_borderline	no	possibly_accessible	inner_leaflet_anchored	Src-family tyrosine kinase; canonically inner-leaflet myristoylated/palmitoylated. **Cell-surface LYN reported on B cells and in some cancer contexts**, parallel to ecto-SRC. Borderline pathological surfacing.	HGNC:6735	LYN	4067	ENSG00000254087	ENSP00000428924.1	2	no	inner_leaflet_anchored
HCK	P08631	wrong_side_negative	no	unlikely	inner_leaflet_anchored	Hematopoietic cell kinase (Src family); inner-leaflet lipid-anchored.	HGNC:4840	HCK	3055	ENSG00000101336	ENSP00000365012.3	2	no	inner_leaflet_anchored
NRAS	P01111	wrong_side_negative	no	unlikely	inner_leaflet_anchored	Ras GTPase; lipidated inner leaflet (same family as KRAS in benchmark).	HGNC:7989	NRAS	4893	ENSG00000213281	ENSP00000358548.4	1	no	inner_leaflet_anchored
RAC1	P63000	wrong_side_negative	no	unlikely	inner_leaflet_anchored	Rac1 GTPase; geranylgeranylated to inner leaflet.	HGNC:9801	RAC1	5879	ENSG00000136238	ENSP00000258737.7	1	no	inner_leaflet_anchored
RPN1	P04843	wrong_compartment_negative	no	unlikely	endomembrane_resident	Ribophorin 1; ER membrane subunit of OST glycosylation complex.	HGNC:10381	RPN1	6184	ENSG00000163902	ENSP00000296255.3	2	no	endomembrane_resident
RPN2	P04844	wrong_compartment_negative	no	unlikely	endomembrane_resident	Ribophorin 2; ER membrane subunit of OST.	HGNC:10382	RPN2	6185	ENSG00000118705	ENSP00000237530.6	1	no	endomembrane_resident
SCAP	Q12770	wrong_compartment_negative	no	unlikely	endomembrane_resident	SREBP cleavage-activating protein; ER cholesterol sensor.	HGNC:30634	SCAP	22937	ENSG00000114650	ENSP00000265565.5	2	no	endomembrane_resident
ITPR3	Q14573	wrong_compartment_negative	no	unlikely	endomembrane_resident	IP3 receptor type 3; ER membrane calcium channel.	HGNC:6182	ITPR3	3710	ENSG00000096433	ENSP00000363435.4	2	no	endomembrane_resident
ITPR1	Q14643	wrong_compartment_negative	no	unlikely	endomembrane_resident	IP3 receptor type 1; ER membrane calcium channel.	HGNC:6180	ITPR1	3708	ENSG00000150995	ENSP00000349597.4	1	no	endomembrane_resident
SEC61G	P60059	wrong_compartment_negative	no	unlikely	endomembrane_resident	Sec61 translocon γ subunit; ER protein-translocation channel.	HGNC:18277	SEC61G	23480	ENSG00000132432	ENSP00000341538.4	1	no	endomembrane_resident
B4GALT1	P15291	induced_borderline	contextual	possibly_accessible	tissue_restricted_surface	β-1,4-galactosyltransferase 1; primarily Golgi-resident, but **a cell-surface form on sperm mediates zona pellucida adhesion**; also reported on tumor cells. Conditional/cell-type-restricted surfacing.	HGNC:924	B4GALT1	2683	ENSG00000086062	ENSP00000369055.4	2	contextual	dual_localization
TMED9	Q9BVK6	wrong_compartment_negative	no	unlikely	endomembrane_resident	TMED9 p24-family cargo receptor; ER ↔ ERGIC ↔ cis-Golgi cycling for traffic of GPI-anchored cargo. Golgi-residence dominant; no documented stable PM pool. Adversarial M1 hit testing whether secretory-pathway cycling is conflated with PM accessibility.	HGNC:24878	TMED9	54732	ENSG00000184840	ENSP00000330945.6	1	no	endomembrane_resident
TMED10	P49755	dual_localization_borderline	contextual	possibly_accessible	dual_localization	TMED10 p24-family cargo receptor — same ER-Golgi cycling pattern as TMED9 but with documented minority PM pool from secretory cycling and reports of cell-surface display in some cancer contexts. Distinguishable from TMED9 by the more frequent surface-detection reports; dual-localization with Golgi-dominant residence + minority PM fraction qualifies for contextual / dual_localization.	HGNC:16998	TMED10	10972	ENSG00000170348	ENSP00000303145.4	1	contextual	dual_localization
GALNT1	Q10472	wrong_compartment_negative	no	unlikely	endomembrane_resident	N-acetylgalactosaminyltransferase 1; Golgi glycosyltransferase.	HGNC:4123	GALNT1	2589	ENSG00000141429	ENSP00000269195.4	1	no	endomembrane_resident
NUP210	Q8TEM1	wrong_compartment_negative	no	unlikely	nuclear_envelope	Nuclear pore complex transmembrane component; nuclear envelope.	HGNC:30052	NUP210	23225	ENSG00000132182	ENSP00000254508.5	2	no	nuclear_envelope
SUN1	O94901	wrong_compartment_negative	no	unlikely	nuclear_envelope	SUN domain protein 1; inner nuclear membrane (LINC complex).	HGNC:18587	SUN1	23353	ENSG00000164828	ENSP00000374225.3	1	no	nuclear_envelope
SUN2	Q9UH99	wrong_compartment_negative	no	unlikely	nuclear_envelope	SUN domain protein 2; inner nuclear membrane.	HGNC:14210	SUN2	25777	ENSG00000100242	ENSP00000385616.1	1	no	nuclear_envelope
SYNE1	Q8NF91	wrong_compartment_negative	no	unlikely	nuclear_envelope	Nesprin-1; outer nuclear membrane (LINC complex), cytoskeleton-coupled.	HGNC:17089	SYNE1	23345	ENSG00000131018	ENSP00000356222.4	1	no	nuclear_envelope
SYNE2	Q8WXH0	wrong_compartment_negative	no	unlikely	nuclear_envelope	Nesprin-2; outer nuclear membrane.	HGNC:17084	SYNE2	23224	ENSG00000054654	ENSP00000344528.5	1	no	nuclear_envelope
VDAC1	P21796	induced_borderline	contextual	possibly_accessible	dual_localization	Mitochondrial outer-membrane porin; **plasma-membrane VDAC1 (pl-VDAC) is well-documented** in B cells, neurons, sperm, cancer cells, erythrocytes. Anti-VDAC1 antibodies in development. Borderline due to dual-localization.	HGNC:12669	VDAC1	7416	ENSG00000213585	ENSP00000265333.3	1	contextual	dual_localization
BAX	Q07812	induced_borderline	no	possibly_accessible	cytoplasmic	Pro-apoptotic Bcl-2 family; canonically translocates to mitochondrial outer membrane during apoptosis. **Surface BAX has been reported as an apoptotic-cell marker** (parallel to CALR's ICD-induced surface translocation).	HGNC:959	BAX	581	ENSG00000087088	ENSP00000293288.8	1	no	cytoplasmic
TGFB1	P01137	surface_attachment_borderline	contextual	possibly_accessible	stable_surface_attachment	TGF-β1 is secreted as a precursor cleaved into LAP + mature TGF-β1 (small latent complex). On Tregs / platelets the complex is **covalently disulfide-bonded to surface GARP (LRRC32)** via specific intermolecular cysteine pairs, co-trafficked from the ER as a single unit. Livmoniplimab (ABBV-151) is a clinical antibody specifically targeting the GARP:latent-TGF-β1 complex. Covalent surface attachment is the right mechanism category.	HGNC:11766	TGFB1	7040	ENSG00000105329	ENSP00000221930.4	3	contextual	stable_surface_attachment
C3	P01024	surface_attachment_borderline	contextual	possibly_accessible	stable_surface_attachment	Complement C3 secreted plasma protein; cleavage fragment **C3b is covalently deposited on cell surfaces during opsonization**. Borderline because C3 itself is soluble but its activation product is surface-anchored.	HGNC:1318	C3	718	ENSG00000125730	ENSP00000245907.4	2	no	secreted_only
TF	P02787	secreted_negative	no	unlikely	secreted_only	Transferrin; secreted iron-transport plasma protein.	HGNC:11740	TF	7018	ENSG00000091513	ENSP00000385834.3	2	no	secreted_only
IL6	P05231	secreted_negative	no	unlikely	secreted_only	Interleukin-6; secreted cytokine.	HGNC:6018	IL6	3569	ENSG00000136244	ENSP00000258743.5	1	no	secreted_only
IGF1	P05019	secreted_negative	no	unlikely	secreted_only	Insulin-like growth factor 1; secreted hormone.	HGNC:5464	IGF1	3479	ENSG00000017427	ENSP00000302665.8	1	no	secreted_only
F2	P00734	secreted_negative	no	unlikely	secreted_only	Prothrombin secreted coagulation zymogen. Recruits to activated-platelet surfaces during prothrombinase-complex assembly via Gla-domain binding to phosphatidylserine, but **the protein has no membrane anchor of its own** — surface association is via Ca²⁺-dependent reversible binding, not membrane insertion. Recruitment ≠ surface accessibility.	HGNC:3535	F2	2147	ENSG00000180210	ENSP00000308541.5	2	no	secreted_only
FN1	P02751	secreted_negative	contextual	unlikely	stable_surface_attachment	Fibronectin secreted ECM glycoprotein. Forms cell-surface fibronectin matrix via integrin α5β1 binding (recruitment), and EDB-fibronectin antibodies target tumor-stromal fibronectin, but **the protein has no membrane anchor of its own** — it's a soluble protein that binds surface receptors. Recruitment ≠ surface accessibility.	HGNC:3778	FN1	2335	ENSG00000115414	ENSP00000323534.6	1	contextual	stable_surface_attachment
APOB	P04114	secreted_negative	no	unlikely	secreted_only	Apolipoprotein B-100; secreted on lipoprotein particles.	HGNC:603	APOB	338	ENSG00000084674	ENSP00000233242.1	1	no	secreted_only
VEGFA	P15692	secreted_negative	no	unlikely	secreted_only	Vascular endothelial growth factor A; secreted angiogenic factor.	HGNC:12680	VEGFA	7422	ENSG00000112715	ENSP00000317598.7	1	no	secreted_only
A2M	P01023	secreted_negative	no	unlikely	secreted_only	α2-macroglobulin; secreted plasma protease inhibitor.	HGNC:7	A2M	2	ENSG00000175899	ENSP00000323929.8	1	no	secreted_only
JAK3	P52333	approved_drug_intracellular_negative	no	unlikely	cytoplasmic	JAK3 tyrosine kinase; cytoplasmic (associates with γc of cytokine receptors). Tofacitinib target.	HGNC:6193	JAK3	3718	ENSG00000105639	ENSP00000391676.1	2	no	cytoplasmic
SYK	P43405	approved_drug_intracellular_negative	no	unlikely	cytoplasmic	Spleen tyrosine kinase; cytoplasmic. Fostamatinib target.	HGNC:11491	SYK	6850	ENSG00000165025	ENSP00000364898.1	2	no	cytoplasmic
BRAF	P15056	approved_drug_intracellular_negative	no	unlikely	cytoplasmic	"B-Raf serine/threonine kinase; cytoplasmic. **Vemurafenib/dabrafenib approved**. Tests ""approved drug ⇒ surface"" trap."	HGNC:1097	BRAF	673	ENSG00000157764	ENSP00000493543.1	1	no	cytoplasmic
BTK	Q06187	approved_drug_intracellular_negative	no	unlikely	cytoplasmic	Bruton's tyrosine kinase; cytoplasmic. **Ibrutinib approved**.	HGNC:1133	BTK	695	ENSG00000010671	ENSP00000308176.8	1	no	inner_leaflet_anchored
JAK1	P23458	approved_drug_intracellular_negative	no	unlikely	cytoplasmic	JAK1 tyrosine kinase; cytoplasmic. Multiple approved JAK inhibitors.	HGNC:6190	JAK1	3716	ENSG00000162434	ENSP00000343204.4	1	no	inner_leaflet_anchored
JAK2	O60674	approved_drug_intracellular_negative	no	unlikely	cytoplasmic	JAK2 tyrosine kinase; cytoplasmic. **Ruxolitinib approved** (myelofibrosis).	HGNC:6192	JAK2	3717	ENSG00000096968	ENSP00000371067.4	1	no	inner_leaflet_anchored
TYK2	P29597	approved_drug_intracellular_negative	no	unlikely	cytoplasmic	TYK2 tyrosine kinase; cytoplasmic. Deucravacitinib approved (psoriasis).	HGNC:12440	TYK2	7297	ENSG00000105397	ENSP00000431885.1	1	no	cytoplasmic
AKT2	P31751	approved_drug_intracellular_negative	no	unlikely	cytoplasmic	AKT2 serine/threonine kinase; cytoplasmic. Capivasertib clinical/approved.	HGNC:392	AKT2	208	ENSG00000105221	ENSP00000309428.6	1	no	inner_leaflet_anchored
MAP2K1	Q02750	approved_drug_intracellular_negative	no	unlikely	cytoplasmic	MEK1 kinase; cytoplasmic. **Cobimetinib/trametinib approved**.	HGNC:6840	MAP2K1	5604	ENSG00000169032	ENSP00000302486.5	1	no	cytoplasmic
MAP2K2	P36507	approved_drug_intracellular_negative	no	unlikely	cytoplasmic	MEK2 kinase; cytoplasmic.	HGNC:6842	MAP2K2	5605	ENSG00000126934	ENSP00000262948.4	1	no	cytoplasmic
HDAC6	Q9UBN7	approved_drug_intracellular_negative	no	unlikely	cytoplasmic	Histone deacetylase 6; cytoplasmic/perinuclear with no membrane anchor. 'Extracellular HDAC6' reports are mostly vesicular cargo (in EVs, not cell-surface accessible) or recruitment-style binding. **No own membrane anchor** — recruitment ≠ surface accessibility. Multiple clinical small-molecule inhibitors target the intracellular catalytic pocket.	HGNC:14064	HDAC6	10013	ENSG00000094631	ENSP00000334061.5	1	no	cytoplasmic
IKBKB	O14920	approved_drug_intracellular_negative	no	unlikely	cytoplasmic	IKK-β; cytoplasmic. Multiple clinical NF-κB-pathway programs.	HGNC:5960	IKBKB	3551	ENSG00000104365	ENSP00000430684.1	1	no	cytoplasmic
LRRK2	Q5S007	approved_drug_intracellular_negative	no	unlikely	cytoplasmic	LRRK2 kinase; cytoplasmic/peripheral. **Parkinson's clinical programs**.	HGNC:18618	LRRK2	120892	ENSG00000188906	ENSP00000298910.7	1	no	cytoplasmic
STIM1	Q13586	induced_borderline	contextual	possibly_accessible	dual_localization	ER calcium sensor; canonically ER-resident, but **clusters at ER-PM junctions during store-operated calcium entry (SOCE)**; some PM staining reports. Borderline due to ER-PM junction localization.	HGNC:11386	STIM1	6786	ENSG00000167323	ENSP00000300737.4	4	yes	classical_surface_receptor
TFRC	P02786	disagreement_rich_positive	yes	likely_accessible	classical_surface_receptor	Transferrin receptor 1 (CD71); classical iron-uptake receptor; **multiple clinical antibody programs** (CX-2029 EpCAM-conditional ADC, TROP-2/TFRC dual-targeting), plus the standard transferrin-conjugate brain-shuttle approaches. Type II single-pass TM with large ECD. Missed by SURFY and HPA despite being a canonical surface receptor.	HGNC:11763	TFRC	7037	ENSG00000072274	ENSP00000353224.4	3	yes	classical_surface_receptor
B2M	P61769	stable_complex_positive	yes	likely_accessible	stable_complex_partner	β2-microglobulin; structural light chain of MHC class I (and CD1 family). **No anchor of its own**, but is stably present on the surface of every nucleated cell as the non-covalent partner of TM-anchored MHC-I heavy chain — assembled in the ER and co-trafficked. Canonical example of accessibility via stable complex partnership. Clinical anti-B2M programs exist (historical mAb work, current B2M-directed CAR-T approaches in multiple myeloma).	HGNC:914	B2M	567	ENSG00000166710	ENSP00000453350.1	3	yes	stable_complex_partner
LRRC32	Q14392	disagreement_rich_positive	yes	likely_accessible	classical_surface_receptor	GARP — single-pass type I TM glycoprotein with a large LRR extracellular domain. Restricted expression on Tregs and platelets. Anchors latent TGF-β1 to the cell surface via covalent disulfide bonds. Clinical antibody program: **livmoniplimab (ABBV-151)** targets the GARP:latent-TGF-β1 complex in solid-tumor combination trials with anti-PD1.	HGNC:4161	LRRC32	2615	ENSG00000137507	ENSP00000260061.5	4	yes	classical_surface_receptor
LAMP2	P13473	induced_borderline	contextual	possibly_accessible	lysosomal_exocytosis	Second canonical lysosomal membrane glycoprotein (CD107b). Reaches the PM via lysosomal exocytosis on activated cytotoxic lymphocytes / NK cells — same conditional-surfacing mechanism as LAMP1. Surface staining is a marker of degranulation.	HGNC:6501	LAMP2	3920	ENSG00000005893	ENSP00000200639.4	3	contextual	lysosomal_exocytosis
OR1A1	Q9P1Q5	disagreement_rich_positive	yes	likely_accessible	multipass_with_exposed_loops	Olfactory receptor 1A1 — classical 7TM rhodopsin-family GPCR. Stably surface on olfactory sensory neurons (and reported in some ectopic-expression contexts). Expression is tissue-restricted to a specialized cell type but the surface architecture is unambiguous when expressed.	HGNC:8179	OR1A1	8383	ENSG00000172146	ENSP00000492897.1	2	yes	multipass_with_exposed_loops
DSG3	P32926	disagreement_rich_positive	yes	likely_accessible	classical_surface_receptor	Desmoglein 3 — single-pass type I TM cadherin in desmosomes of basal keratinocytes and oral mucosa. **Pemphigus vulgaris autoantigen** — patient autoantibodies bind cell-surface DSG3 on keratinocytes (validation of surface accessibility). Tissue-restricted expression.	HGNC:3050	DSG3	1830	ENSG00000134757	ENSP00000257189.4	3	yes	classical_surface_receptor
GYPA	P02724	disagreement_rich_positive	yes	likely_accessible	classical_surface_receptor	Glycophorin A (MNS blood group antigen) — single-pass type I TM sialoglycoprotein on the erythrocyte surface. Classical surface architecture; RBC-restricted expression. Targeted by anti-GYPA in blood-group serology and as an RBC marker in clinical immunology.	HGNC:4702	GYPA	2993	ENSG00000170180	ENSP00000324483.10	3	yes	classical_surface_receptor
PRNP	P04156	gpi_anchored_positive	yes	likely_accessible	gpi_anchored	Cellular prion protein — canonical GPI-anchored outer-leaflet protein, abundant on neurons. Dominant localization is the plasma membrane; intracellular pools are routine biosynthesis / endolysosomal recycling. Anti-PRNP antibodies recognize the surface form clinically; conformational variant PrP^Sc is the disease antigen.	HGNC:9449	PRNP	5621	ENSG00000171867	ENSP00000368752.4	3	yes	gpi_anchored
NRROS	Q86YC3	disagreement_rich_positive	yes	likely_accessible	classical_surface_receptor	NRROS (legacy alias LRRC33) — single-pass type I TM glycoprotein with a large LRR extracellular domain on myeloid cells (microglia, monocytes); the myeloid-cell analog of GARP / LRRC32 on Tregs. Anchors latent TGF-β1 to the cell surface via covalent disulfide bonds; clinical antibody programs target the NRROS:latent-TGF-β1 complex in CNS / myeloid contexts.	HGNC:24613	NRROS	375387	ENSG00000174004	ENSP00000328625.4	3	contextual	tissue_restricted_surface
HSPD1	P10809	dual_localization_borderline	contextual	possibly_accessible	dual_localization	HSP60 — canonically mitochondrial matrix chaperonin. **Reported on the cell surface** in tumor cells, stress contexts, and as a damage-associated molecular pattern (DAMP). Mechanism of surface translocation is debated (chaperone export, mitochondrial leakage, vesicular). Tests whether the model recognizes the minority-surface dual-localization pattern.	HGNC:5261	HSPD1	3329	ENSG00000144381	ENSP00000340019.2	1	contextual	cell_state_induced
MSLN	Q13421	gpi_anchored_positive	yes	likely_accessible	gpi_anchored	Mesothelin — GPI-anchored on the outer leaflet of mesothelial cells and overexpressed in mesothelioma / ovarian / pancreatic / lung adenocarcinoma. Clinical anti-MSLN ADC (anetumab ravtansine), CAR-T, and bispecific programs. 4/7 surface DB sources flag it; classical GPI mechanism.	HGNC:7371	MSLN	10232	ENSG00000102854	ENSP00000372313.3	4	yes	gpi_anchored
CEACAM5	P06731	gpi_anchored_positive	yes	likely_accessible	gpi_anchored	Carcinoembryonic antigen (CEA) — GPI-anchored, oncofetal surface antigen on epithelial tumors. Tusamitamab ravtansine (anti-CEACAM5 ADC) in clinical trials; classical clinical surface target. 4/7 surface DB sources.	HGNC:1817	CEACAM5	1048	ENSG00000105388	ENSP00000221992.5	4	yes	gpi_anchored
CD24	P25063	gpi_anchored_positive	yes	likely_accessible	gpi_anchored	CD24 — small GPI-anchored sialoglycoprotein on B cells, neutrophils, and many tumors. Macrophage 'don't eat me' signal via Siglec-10. Clinical-stage anti-CD24 antibodies (e.g. SNS-101). 2/7 surface DB sources — disagreement-rich GPI.	HGNC:1645	CD24	100133941	ENSG00000272398	ENSP00000475625.1	2	yes	gpi_anchored
BST2	Q10589	gpi_anchored_positive	yes	likely_accessible	gpi_anchored	Tetherin (BST-2 / CD317) — interferon-induced GPI-anchored antiviral. Unusual N-terminal TM + C-terminal GPI dual-anchor architecture but functionally outer-leaflet on the cell surface. 4/7 surface DB sources.	HGNC:1119	BST2	684	ENSG00000130303	ENSP00000252593.6	4	yes	gpi_anchored
DPEP1	P16444	gpi_anchored_positive	yes	likely_accessible	gpi_anchored	Renal dipeptidase — GPI-anchored ectoenzyme on kidney brush border, lung endothelium, and colon cancer. Clinical-stage anti-DPEP1 antibody (LSALT peptide / DC-101 platform). 4/7 surface DB sources; classical GPI.	HGNC:3002	DPEP1	1800	ENSG00000015413	ENSP00000261615.4	4	yes	gpi_anchored
ZP3	P21754	dual_localization_borderline	contextual	possibly_accessible	dual_localization	Zona pellucida glycoprotein 3 — single-pass TM precursor at the oocyte surface; furin cleavage releases the ectodomain into the surrounding zona pellucida matrix during oogenesis. The TM-anchored precursor stage is the textbook `dual_localization` pattern (parallel to EREG): a TM precursor that transits the PM before regulated proteolysis releases the dominant form. The mature matrix-deposited ZP3 itself is `secreted_only` (no own anchor), but the documented TM-precursor stage on the oocyte PM is enough for `contextual / dual_localization`. Restricted to the female germline / oocyte lineage.	HGNC:13189	ZP3	7784	ENSG00000188372	ENSP00000337310.4	2	contextual	tissue_restricted_surface
IZUMO1	Q8IYV9	induced_borderline	contextual	possibly_accessible	cell_state_induced	IZUMO1 — single-pass TM with Ig-like extracellular domain, required for sperm-egg fusion. **Sequestered in the acrosomal cap of spermatids at baseline; PM-exposed only after the acrosome reaction** (a sperm-specific cell-state event). Target of contraceptive immunology research. 2/7 surface DB sources.	HGNC:28539	IZUMO1	284359	ENSG00000182264	ENSP00000327786.2	2	contextual	tissue_restricted_surface
DSG4	Q86SJ6	disagreement_rich_positive	yes	likely_accessible	classical_surface_receptor	Desmoglein 4 — type I single-pass TM cadherin restricted to hair follicle and stratified epithelia. Same classical TM cadherin architecture as DSG1/2/3 — tissue-restricted expression, classical surface mechanism where expressed. 3/7 surface DB sources.	HGNC:21307	DSG4	147409	ENSG00000175065	ENSP00000311859.4	3	yes	classical_surface_receptor
LAMP3	Q9UQV4	lysosomal_exocytosis_borderline	contextual	possibly_accessible	lysosomal_exocytosis	DC-LAMP (CD208) — third member of the LAMP family. Single-pass TM glycoprotein on late-endosomal / lysosomal membranes in mature dendritic cells. Reaches the PM via lysosomal exocytosis during DC maturation and antigen presentation. 3/7 surface DB sources.	HGNC:14582	LAMP3	27074	ENSG00000078081	ENSP00000265598.3	3	contextual	lysosomal_exocytosis
CD63	P08962	lysosomal_exocytosis_borderline	contextual	possibly_accessible	lysosomal_exocytosis	CD63 (LAMP-3 in old literature; tetraspanin TSPAN30) — multi-pass tetraspanin on late-endosomes / MVBs / lysosomes. Reaches the PM via lysosomal exocytosis and is a canonical exosomal-surface marker. Surface-displayed in activated platelets and degranulating immune cells. 4/7 surface DB sources.	HGNC:1692	CD63	967	ENSG00000135404	ENSP00000257857.4	4	contextual	lysosomal_exocytosis
CD68	P34810	lysosomal_exocytosis_borderline	contextual	possibly_accessible	lysosomal_exocytosis	Macrosialin / CD68 — single-pass TM sialomucin on macrophage / monocyte late-endosomes and lysosomes. Cycles to the PM during phagocytosis / lysosomal exocytosis. Used as a histological pan-macrophage marker; clinical anti-CD68 imaging agents in development. 3/7 surface DB sources.	HGNC:1693	CD68	968	ENSG00000129226	ENSP00000250092.6	3	contextual	dual_localization
SCARB2	Q14108	lysosomal_exocytosis_borderline	contextual	possibly_accessible	lysosomal_exocytosis	LIMP-2 (SCARB2) — multi-pass TM lysosomal integral membrane protein, mannose-6-phosphate-independent receptor for β-glucocerebrosidase trafficking to lysosomes. Reaches the PM via lysosomal exocytosis; also the cellular entry receptor for enterovirus 71. 2/7 surface DB sources.	HGNC:1665	SCARB2	950	ENSG00000138760	ENSP00000264896.2	2	contextual	lysosomal_exocytosis
HMGB1	P09429	induced_borderline	contextual	possibly_accessible	cell_state_induced	High mobility group box 1 — chromatin-binding nuclear protein and soluble DAMP, but **surface-displayed on activated platelets**: cytoplasmic translocation followed by plasma-membrane exposure detected by flow cytometry and immunofluorescence on viable thrombin/collagen-activated platelets, including HMGB1+ microparticles released into circulation (Maugeri et al. 2014, PMID 24634472; Vogel et al. 2015, PMID 26330544). Contextual surface accessibility — restricted to the activated-platelet cell state (and HMGB1+ EV exteriors in inflammatory disease), not constitutive on nucleated cells.	HGNC:4983	HMGB1	3146	ENSG00000189403	ENSP00000343040.4	1	contextual	cell_state_induced
HNRNPK	P61978	nuclear_negative	no	unlikely	nuclear	Heterogeneous nuclear ribonucleoprotein K — nucleoplasmic RNA-binding protein involved in pre-mRNA processing. No documented membrane anchor; ectopic surface reports in tumor proteomics studies are likely contamination. Adversarial M1 hit (1 CSPA mass-spec source).	HGNC:5044	HNRNPK	3190	ENSG00000165119	ENSP00000353552.5	1	no	nuclear
ATP5F1B	P06576	dual_localization_borderline	contextual	possibly_accessible	dual_localization	ATP synthase F1 β subunit — primarily a mitochondrial matrix component of complex V. **Plasma-membrane 'ecto-F1-ATPase' is documented** on hepatocytes (HDL receptor), endothelium (apoA-I receptor), and multiple tumor lineages; multiple anti-ecto-ATP-synthase antibody / aptamer programs. Minority but stable PM pool alongside the dominant mitochondrial localization.	HGNC:830	ATP5F1B	506	ENSG00000110955	ENSP00000262030.3	1	contextual	cell_state_induced
IZUMO4	Q1ZYL8	induced_borderline	no	possibly_accessible	endomembrane_resident	IZUMO4 — IZUMO family single-pass TM with Ig-like ECD; same acrosomal-cap → PM trafficking biology as IZUMO1 (sequestered in the acrosomal cap of spermatids at baseline; PM-exposed after the acrosome reaction). Forms heterodimer with IZUMO1 during sperm-egg fusion. 0/5 surface DB sources.	HGNC:26950	IZUMO4	113177	ENSG00000099840	ENSP00000378712.3	0	no	nuclear
CRISP1	P54107	surface_attachment_borderline	contextual	possibly_accessible	stable_surface_attachment	CRISP1 (AEG / DE) — CAP-superfamily glycoprotein secreted by epididymal epithelium that **stably attaches to the sperm plasma membrane during epididymal maturation in a wash-resistant manner** (mechanism candidates: GPI re-tethering, disulfide cross-linking, or very stable non-covalent association). Surface-accessible on ejaculated mature sperm through transit and fertilization; anti-CRISP1 contraceptive immunology programs. 0/5 surface DB sources.	HGNC:304	CRISP1	167	ENSG00000124812	ENSP00000331317.5	0	contextual	stable_surface_attachment
EPCAM	P16422	disagreement_rich_positive	yes	likely_accessible	classical_surface_receptor	Epithelial cell adhesion molecule — single-pass type I TM glycoprotein on epithelial cells. Cytokeratin-positive carcinoma marker; catumaxomab (anti-EpCAM x CD3 trifunctional, EMA-approved 2009 then voluntarily withdrawn 2017); solitomab and multiple EpCAM-targeted bispecifics / CAR-T programs clinical. 5/5 surface DB sources.	HGNC:11529	EPCAM	4072	ENSG00000119888	ENSP00000263735.4	5	yes	classical_surface_receptor
CSPG4	Q6UVK1	disagreement_rich_positive	yes	likely_accessible	classical_surface_receptor	Melanoma chondroitin sulfate proteoglycan (CSPG4 / MCSP / NG2) — single-pass type I TM chondroitin-sulfate proteoglycan on melanoma, glioma, sarcoma. Clinical anti-CSPG4 CAR-T programs. 5/5 surface DB sources.	HGNC:2466	CSPG4	1464	ENSG00000173546	ENSP00000312506.5	5	yes	classical_surface_receptor
TACSTD2	P09758	validated_positive	yes	likely_accessible	classical_surface_receptor	TROP-2 / TACSTD2 — single-pass type I TM glycoprotein on epithelial tumors. **Sacituzumab govitecan (Trodelvy) approved** 2020 for mTNBC and urothelial; datopotamab deruxtecan (Dato-DXd) approved 2024. 5/5 surface DB sources.	HGNC:11530	TACSTD2	4070	ENSG00000184292	ENSP00000360269.2	5	yes	classical_surface_receptor
CD276	Q5ZPR3	disagreement_rich_positive	yes	likely_accessible	classical_surface_receptor	B7-H3 / CD276 — single-pass type I TM Ig-superfamily checkpoint molecule on tumor cells and tumor stroma. Multiple clinical ADC / CAR-T / radioligand programs (ifinatamab deruxtecan, omburtamab radioconjugate, mirzotamab clezutoclax). 4/5 surface DB sources.	HGNC:19137	CD276	80381	ENSG00000103855	ENSP00000320058.5	4	yes	classical_surface_receptor
CEACAM6	P40199	gpi_anchored_positive	yes	likely_accessible	gpi_anchored	CEACAM6 / NCA / CD66c — GPI-anchored carcinoembryonic-antigen family member on epithelial tumors. Multiple anti-CEACAM6 ADC / mAb / CAR-T programs (NEO-201, tinurilimab / BAY1834942). 4/5 surface DB sources.	HGNC:1818	CEACAM6	4680	ENSG00000086548	ENSP00000199764.6	4	yes	gpi_anchored
MUC16	Q8WXI7	disagreement_rich_positive	yes	likely_accessible	classical_surface_receptor	MUC16 / CA-125 — single-pass type I TM with a massive O-glycosylated mucin ectodomain; ovarian-cancer serum biomarker and surface antigen. Oregovomab clinical; ubamatamab and multiple mucin-targeted T-cell engagers / ADCs. 4/5 surface DB sources.	HGNC:15582	MUC16	94025	ENSG00000181143	ENSP00000381008.2	4	yes	classical_surface_receptor
PTK7	Q13308	disagreement_rich_positive	yes	likely_accessible	classical_surface_receptor	Protein tyrosine kinase 7 — single-pass type I TM pseudokinase and Wnt-pathway co-receptor; oncofetal antigen on multiple carcinomas. Cofetuzumab pelidotin (PF-06647020) anti-PTK7 ADC clinical. 4/5 surface DB sources.	HGNC:9618	PTK7	5754	ENSG00000112655	ENSP00000230418.4	4	yes	classical_surface_receptor
CLDN18	P56856	disagreement_rich_positive	yes	likely_accessible	multipass_with_exposed_loops	Claudin-18 isoform 2 (CLDN18.2) — 4-pass TM tight-junction claudin, gastric-restricted isoform. **Zolbetuximab (Vyloy) approved** 2024 for HER2-negative gastric / GEJ adenocarcinoma; multiple CAR-CLDN18.2 T-cell programs in clinic. Tissue-restricted to gastric epithelia but architectural surface story is unambiguous. 3/5 surface DB sources.	HGNC:2039	CLDN18	51208	ENSG00000066405	ENSP00000183605.5	3	yes	multipass_with_exposed_loops
FOLH1	Q04609	validated_positive	yes	likely_accessible	classical_surface_receptor	PSMA / folate hydrolase 1 — single-pass type II TM with a large extracellular glutamate-carboxypeptidase domain; prostate-cancer overexpressed. **Lutetium-PSMA-617 (Pluvicto) approved** 2022 for metastatic CRPC; multiple PSMA radioligands and PSMA-CAR-T programs. 3/5 surface DB sources.	HGNC:3788	FOLH1	2346	ENSG00000086205	ENSP00000256999.2	3	yes	classical_surface_receptor
GPC3	P51654	gpi_anchored_positive	yes	likely_accessible	gpi_anchored	Glypican-3 — GPI-anchored heparan sulfate proteoglycan on hepatocellular carcinoma. Codrituzumab (GC33) clinical mAb; multiple GPC3-CAR-T programs in clinical development. 3/5 surface DB sources.	HGNC:4451	GPC3	2719	ENSG00000147257	ENSP00000359854.3	3	yes	gpi_anchored
NECTIN4	Q96NY8	validated_positive	yes	likely_accessible	classical_surface_receptor	Nectin-4 — single-pass type I TM Ig-superfamily adhesion molecule on urothelial / breast / lung cancers. **Enfortumab vedotin (Padcev) approved** 2019 for urothelial cancer. 3/5 surface DB sources.	HGNC:19688	NECTIN4	81607	ENSG00000143217	ENSP00000356991.3	3	yes	classical_surface_receptor
CA9	Q16790	disagreement_rich_positive	yes	likely_accessible	classical_surface_receptor	Carbonic anhydrase IX — single-pass type I TM with extracellular PG + catalytic CA domain; hypoxia-induced HIF target on clear-cell RCC. **Girentuximab approved diagnostic** (PET imaging) 2024; therapeutic CA9-ADC and CAR-T programs clinical. 2/5 surface DB sources.	HGNC:1383	CA9	768	ENSG00000107159	ENSP00000367608.4	2	yes	classical_surface_receptor
DLK1	P80370	disagreement_rich_positive	yes	likely_accessible	classical_surface_receptor	Delta-like non-canonical Notch ligand 1 (DLK1 / pref-1) — single-pass type I TM with EGF-like repeats; oncofetal antigen on neuroblastoma, hepatoblastoma, adrenal cortex carcinoma. ADCT-701 anti-DLK1 ADC clinical. ADAM17 ectodomain shedding releases a soluble form, but the TM precursor IS the surface form. 2/5 surface DB sources.	HGNC:2907	DLK1	8788	ENSG00000185559	ENSP00000331081.6	2	contextual	dual_localization
GPC2	Q8N158	gpi_anchored_positive	yes	likely_accessible	gpi_anchored	Glypican-2 — GPI-anchored heparan sulfate proteoglycan; oncofetal antigen on neuroblastoma. CHOP D3-based GPC2-CAR-T programs in clinical development. 2/5 surface DB sources.	HGNC:4450	GPC2	221914	ENSG00000213420	ENSP00000292377.2	2	yes	gpi_anchored
LYPD1	Q8N2G4	gpi_anchored_positive	yes	likely_accessible	gpi_anchored	LY6/PLAUR domain containing 1 — GPI-anchored LY6/uPAR-family surface protein; emerging tumor-associated antigen. 2/5 surface DB sources.	HGNC:28431	LYPD1	116372	ENSG00000150551	ENSP00000340563.6	2	yes	gpi_anchored
SSTR2	P30874	gpcr_extracellular_pocket	yes	likely_accessible	multipass_with_exposed_loops	Somatostatin receptor 2 — 7TM rhodopsin-family GPCR on neuroendocrine tumors. **177Lu-DOTATATE (Lutathera) approved** 2018 for GEP-NETs; multiple SSTR-targeted radioligands and bispecifics. 2/5 surface DB sources.	HGNC:11331	SSTR2	6752	ENSG00000180616	ENSP00000350198.2	2	yes	multipass_with_exposed_loops
TYRP1	P17643	dual_localization_borderline	contextual	possibly_accessible	dual_localization	Tyrosinase-related protein 1 — single-pass type I TM melanin-biosynthesis enzyme. **Canonical dominant compartment is the melanosome** (lysosome-related organelle); surface display on melanoma cells documented and clinically targeted (TA99 mAb, anti-TYRP1 ADC programs). Dual-localization biology: melanosomal-dominant with documented melanoma-cell-surface fraction. Borderline analog of PMEL but with cleaner surface evidence. 2/5 surface DB sources.	HGNC:12450	TYRP1	7306	ENSG00000107165	ENSP00000373570.4	2	contextual	lysosomal_exocytosis
STEAP2	Q8NFT2	disagreement_rich_positive	yes	likely_accessible	multipass_with_exposed_loops	STEAP family member 2 — 6-pass TM metalloreductase / paralog of STEAP1; prostate-cancer overexpressed. Clinical STEAP2-targeted CAR-T and bispecific programs. **Not detected by any of the 5 retained M1 DBs** — adversarial M1 escape, tests whether the agent recognizes the STEAP1/STEAP2 architecture by family extrapolation. 0/5 surface DB sources.	HGNC:17885	STEAP2	261729	ENSG00000157214	ENSP00000287908.3	0	yes	multipass_with_exposed_loops
AMHR2	Q16671	disagreement_rich_positive	yes	likely_accessible	classical_surface_receptor	Anti-Müllerian hormone receptor 2 — single-pass type I TM serine/threonine kinase receptor (TGF-β receptor superfamily). Surface on developing Müllerian-duct epithelium, granulosa / theca cells, and ovarian cancer. Clinical anti-AMHR2 ADC and CAR-T programs (e.g., murlentamab). Architectural surface story is unambiguous despite low DB cover. 2/5 surface DB sources (UP, SFY).	HGNC:465	AMHR2	269	ENSG00000135409	ENSP00000257863.3	2	yes	classical_surface_receptor
TM4SF1	P30408	disagreement_rich_positive	yes	likely_accessible	multipass_with_exposed_loops	TM4SF1 / L6 — 4-pass TM tetraspanin-superfamily surface protein on lung / colorectal / pancreatic / breast carcinoma and tumor endothelium. Multiple clinical anti-TM4SF1 ADC programs. Same tetraspanin architecture as CD63 (also in benchmark) but more constitutively at the PM. 2/5 surface DB sources (UP, SFY).	HGNC:11853	TM4SF1	4071	ENSG00000169908	ENSP00000304277.3	2	yes	multipass_with_exposed_loops
ALPG	P10696	disagreement_rich_positive	contextual	possibly_accessible	tissue_restricted_surface	ALPG (legacy alias ALPPL2) — germ cell alkaline phosphatase, GPI-anchored ectoenzyme. When expressed (testis, placenta, germ-cell tumors, oncofetal pattern), the protein is stably surface-displayed; expression itself is narrow / tissue-restricted (cancer-testis pattern). Multiple clinical anti-ALPPL2 ADC/CAR-T programs. contextual/tissue_restricted_surface captures the expression-restricted cancer-testis surface pattern.	HGNC:441	ALPG	251	ENSG00000163286	ENSP00000295453.3	2	contextual	tissue_restricted_surface
LY6K	Q17RY6	gpi_anchored_positive	contextual	possibly_accessible	tissue_restricted_surface	LY6/uPAR family GPI-anchored cancer-testis antigen. Stable GPI display when expressed, but expression is narrow (testis/sperm and cancer cells). contextual/tissue_restricted_surface captures the expression-restricted cancer-testis surface pattern.	HGNC:24225	LY6K	54742	ENSG00000160886	ENSP00000292430.6	2	contextual	tissue_restricted_surface
LYPD3	O95274	gpi_anchored_positive	yes	likely_accessible	gpi_anchored	LYPD3 / C4.4A — LY6/PLAUR domain containing 3, uPAR paralog; GPI-anchored surface protein on lung / pancreatic / esophageal carcinomas. **Lupartumab amadotin (BAY1129980), anti-LYPD3 ADC clinical**. LY6-family GPI architecture is unambiguous. 2/5 surface DB sources (SFY, CSPA).	HGNC:24880	LYPD3	27076	ENSG00000124466	ENSP00000244333.2	2	yes	gpi_anchored