BRAF and melanoma: BRAF mutations are the most frequent changes in melanoma, and they comprise 40–70 % of cases depending on melanoma type.12–14 More than 50 distinct mutations of BRAF gene were reported; ~90 % of them are due to a single nucleotide substitution T1799A at codon position 600 in exon 15 (p.V600E) leading to 500-fold increase in the protein activity.