This ERK pathway is implicated in Huntington's disease. The ligands BDNF, EGF, and Glu bind to their respective receptors (TrkB, EGFR, mGluR) and start a signal transduction pathway starting with RAS and RAF1, which leads to the stimulation of MEK then ERK. ERK promotes function of MSK1 (a downstream kinase), ElK1 and CREB (transcription factors), and caspases 3/7 (apoptotic molecules). These downstream targets are implicated in producing the effects of Huntington's disease at the cellular level. This pathway is based on Figure 1 from Bodai et al. Proteins on this pathway have targeted assays available via the [https://assays.cancer.gov/available_assays?wp_id=WP3853 CPTAC Assay Portal] ccd mutant Huntingtin disease-causing mutation in HTT signaling pathway PW:0000003 Pathway Ontology disease pathway PW:0000013 Pathway Ontology Huntington's disease DOID:12858 Disease 22334892 PubMed A novel target for Huntington's disease: ERK at the crossroads of signaling. The ERK signaling pathway is implicated in Huntington's disease and its upregulation ameliorates pathology. Bioessays 2012 Bodai L Marsh JL Huntington disease pathway PW:0000017 Pathway Ontology