Melanoma is one of the most heterogeneous cancers (35), harboring diverse genomic alterations, including gain of function mutations (e.g., NRAS, BRAF, KIT, CDK4, and MITF), loss of function mutations (e.g., CDKN2A, PTEN, ARID2, and NF), and epigenetic changes (e.g., PTEN, CDKN2A, RAC1, and P53) (36). The gene discussed is PTEN; the disease is melanoma.