NRAS and melanoma: According to the patients’ geographical origin, distribution of mutations among the 451 primary melanomas was significantly heterogeneous for both genes: for BRAF, 109/178 (61%) vs. 114/273 (42%) mutated patients were observed in Sardinian and non-Sardinian populations, respectively (p = 0.0372); for NRAS, 2/105 (2%) vs. 44/207 (21%) mutated cases were observed in Sardinian and non-Sardinian populations (p < 0.0001) (Table 2).