PIK3CA and melanoma: Within this subtype, subgroup 1.1 is characterized by mutations of the gene BRAF (BRAF, a member of the RAF kinase family is the gene most frequently mutated in melanoma) and the other subtypes by BRAF mutations in association with abnormalities of the AKT/PI3K pathways; (b) subtype 2 is characterized at molecular level by mutations of c-Kit; (c) subtype 3 is characterized by mutations in two G proteins: GNAQ and GNA11.