GSTP1 and hepatocellular carcinoma: A recent meta-analysis [40] evaluating GSTP1 methylation in the tissues of 646 subjects with HCC, APC methylation in 592 patients with HCC, and SOCS1 methylation in the tissues of 512 subjects with HCC has shown that hypermethylation of these genes was strongly correlated with HCC risk, and suggested that these epigenetic changes could be valuable diagnostic biomarkers of HCC [40].