A 2015 study analyzed 132 samples obtained from tissues of melanoma patients with disease progression following treatment with BRAF inhibitors, identifying potential mechanisms of resistance in 58% of the cases. Among these cases, 20% had NRAS/KRAS mutations, 30% had BRAF mutations or BRAF amplifications, and 7% had MEK1/2 mutations. This evidence concerns the gene BRAF and melanoma.