MGMT and cancer: Previous studies have reported that EGCG, used as an epigenetic modifier, epigenetically reversed the methylation and expression of silenced genes such as retinoic acid receptor β (RARβ), O6-methylguanine methyltransferase (MGMT), and death-associated protein kinase-1 (DAPK1) by downregulating the DNMT activity in cancer cells [20,42].