The RAS family of GTPases consists of genes including NRAS, KRAS and HRAS mutated in 25, 2 and 1% of melanomas, respectively.5NRAS-mutant melanomas are recognised to be more aggressive and associated with poorer outcomes; however, very little is known about KRAS-mutant melanoma.8KRAS-mutant early brain metastases in our study generally emanated from thin and non-ulcerated primary melanomas (Supplementary Table 7). Here, HRAS is linked to melanoma.