Many fundamental components of key cellular pathways are inactivated in human cancer by hypermethylation including: DNA repair (MLH1, MGMT, BRCA1), cell cycle (p16INK4a, p15INK4b, p14Arf), cell invasion and adherence (E-cadherin, APC, CDH13, VHL), apoptosis (DAPK1, caspase 8), detoxification (GSTP1) and hormonal response (retinoic acid receptor β2 and estrogen receptor). The gene discussed is CDKN2A; the disease is cancer.