KAT7 and hepatocellular carcinoma: Additionally, the downregulation of MiR-639 in HCC cells and tissues is partly due to hypermethylation of the miR-639 promoter by DNMT3A, with the silencing of miR-639 reducing its inhibitory effect on MYST2 and ZEB1, thereby enhancing the proliferation, migration, and invasion of HCC cells [42].