Cancer genomes are characterized by widespread loss of DNA methylation that contribute to genomic instability, and gain of DNA methylation at promoter CpG islands is associated with transcriptional repression7 In melanoma, selected tumor suppressor genes with a critical role in malignant transformation and metastatic behavior, including CDKN2A, PTEN, and CDH11, show frequent promoter hypermethylation and associated transcriptional silencing.8 The gene discussed is PTEN; the disease is melanoma.