Since DNMT1 serves as a crucial element within the epigenetic framework, influencing gene repression by increasing promoter methylation levels, we explored whether DNMT1 mediates the FVTF-downregulating miR-34a-5p promoter methylation, and found that overexpression of DNMT1 restored the methylation levels of most of miR-34a-5p promoter CG sites in the FVTF-treated HCC cells (Fig. 3H), indicating that FVTF demethylates miR-34a-5p promoter by downregulating DNMT1 expression. Here, DNMT1 is linked to hepatocellular carcinoma.