GSTP1 and hepatocellular carcinoma: In HCC, aberrant promoter hypermethylation associated with gene silencing is observed in genes such as SOCS-1, SOCS-3, ASCL, p16INK4a, Ras association domain family 1A (RASSF1A), placental glutathione S transferase P1 (GSTP1) and E-cadherin(8–10,26–29).