DNAm levels of naturally hypermethylated transposable repetitive elements (e.g., LINE-1 and Alu (24–27)) or tumor suppressor genes (e.g., CDKN2A (p16) and CDKN2B (p15) (24, 28, 29)) and oncogenes (e.g., MAGE-A1, H19, MLH1 and MSH2 (26, 28, 30, 31)) were historically used to inform about global methylation modifications in the body, and to make the link between exposure and cancer development. This evidence concerns the gene CDKN2A and cancer.