Alterations in CDKN2A occur in ~60–70% of BRAF, NRAS, and NF1-mutant CMs, whereas wild-type CM has less frequent CDKN2A mutations (~40%) but copy number amplifications of CDK4 (~15%) and CCND1 (~10%), the gene that encodes Cyclin D1, are more common (Genomic Classification of Cutaneous Melanoma, 2015). The gene discussed is NF1; the disease is cutaneous melanoma.