NF1 and melanoma: In contrast, CDKN2A promoter hypermethylation occurs most frequently in NRAS-mutant melanoma (87.7%) and is less common in melanoma with BRAF mutations (67.0% with CDKN2A promoter methylation) and in melanomas with NF1 mutations (77.3% showing CDKN2A promoter methylation) (Table 1).