GSTP1 and hepatocellular carcinoma: Recent studies showed that CpG island hypermethylation-mediated epigenetic silencing of tumor suppressor genes including APC, RASSF1A, SOCS1, HIC1, GSTP1, CDKN2A, RUNX3, and PRDM2 were involved in HCC.3, 4 Notably, SOCS1 ranked first among the altered tumor suppressor genes in HCC cells transfected with miR-29a mimics and inhibitors (Supplementary Figure S5A).