CDKN2A and breast cancer: For breast cancer, some of the genes reported to undergo hypermethylation are involved in evasion of apoptosis (DAPK, TWIST1, HOXA5), cell cycle regulation (p16, CCND2), cell invasion and metastasis (CDH1, APC), DNA repair (BRCA1) and cell signaling (ER and RARβ2) [2].