Moreover, melanomas developed on skin not chronically exposed to sun usually carry either a mutated NRAS or mutated BRAF or concurrently mutated BRAF and PTEN [22]; evidence indeed suggest that BRAF/PTEN and NRAS somatic mutations are mutually exclusive or, in other words, that both mutation subsets does not occur in the same melanoma cell [22-25]. This evidence concerns the gene BRAF and melanoma.