KRAS and melanoma: In addition to BRAF, activating NRAS mutations in cutaneous melanomas (CMs) occur at a rate of 15 to 25% [12–15], and ten to 15% of melanomas have alterations leading to loss of function of NF1. The remaining five to 15% of melanomas includes a variety of genetic alterations (e.g. cKIT, BRAFnon-V600, H-RAS, K-RAS, MEK, etc), all leading to MAPK pathway activation.