One of the most extensively characterized epigenetic alterations in HBV-related HCC is the hypermethylation of CpG islands in tumor suppressor gene promoters, including p16, RASSF1A, E-cadherin, and GSTP1. HBx enhances the expression of DNA methyltransferases (DNMT1, DNMT3A, DNMT3B), promoting transcriptional silencing of these genes (Tian and Ou, 2015; Dandri, 2020). The gene discussed is DNMT1; the disease is hepatocellular carcinoma.