 Approximately 40-60 of cutaneous melanomas select for a mutation in the BRAF protein which is part of a signaling pathway called the Mitogen Activated Protein Kinase MAPK pathway. Over 90 of mutations in BRAF occur at position V600 with the most common being a V600E mutation. Mutation at position V600 of BRAF activates the MAPK pathway which facilitates melanoma proliferation and growth. The response rate to treatment with vemurafenib in patients with stage IV melanoma expressing a V600E BRAF mutation is approximately 50. A phase III study comparing first line treatment with vemurafenib compared to standard dacarbazine chemotherapy demonstrated a statistically significant overall survival benefit in this patient population. Based on this survival benefit vemurafenib was FDA approved for treatment of stage IV melanoma expressing a V600E BRAF mutation. Vemurafenib is administered at a dose of 960 milligrams orally twice daily. 