NRAS and melanoma: In about half of all melanoma patients gain-of-function mutations of the BRAF proto-oncogene [12] are apparent, followed by loss-of-function mutations of the neurofibroma 1 (NF1) [18], and by gain-of-function mutations of the neuroblastoma rat sarcoma (RAS) viral oncogene homolog (NRAS) and the c-KIT proto-oncogene [19].