BRAF and cutaneous melanoma: BRAF mutations occur in ~ 50% of cutaneous melanomas, of which > 80% are BRAFV600E; other mutations activating the RAS-RAF-extracellular signal regulated kinase (ERK) pathway include NRAS (30% of cases) and NF1 (14%) mutations, all usually mutually exclusive, activating RAS-RAF-ERK in > 90% of cutaneous melanomas [13].