GSTP1 and hepatocellular carcinoma: Several studies have revealed that alterations in DNA methylation at many genes, including p15 [79], p16 [80], APC [81], SPINT2 [82], SFRP1 [83], p16INK4a [84], TFPI2 [85], GSTP1 [86] and RASSF1A [87, 88], are associated with the initiation and progression of HCC.