NRAS and melanoma: Four major genetically defined subgroups stratify the patient population into those whose melanoma possess (1) activating BRAFV600 mutations (~50% of patients)5, (2) NRAS mutations (15–20% of patients)6, (3) those with inactivating mutations of NF-1 (~10%, mutually exclusive with BRAF), and (4) those with wild-type BRAF, wild-type NRAS and wild-type cKit (30–35% of patients)7.