NRAS and cancer: We also searched in 180 different cancer sequencing studies (including over 47000 samples using the cBioPortal site) for evidence of BM associated variants, and while all of the detected variants in the 17 genes were found in different cancer types, only 4 variants (NRAS Q61, TP53 E171G, PTEN A328*, ARID2 S297F) were detected corresponding to CNS cancers (n = 10 tumor tissues).