CDKN2A and cancer: Aberrant methylation has been recognized as a hallmark of human cancer, and DNA methylation patterns are altered in all types of cancers analyzed, affecting virtually all cellular pathways trough methylation-mediated silencing of regulator genes such as VHL, p16INK4a, E-cadherin, hMLH1, BRCA1 and LKB1, and many others [9,10].