DNMT3A and neoplasm: Mechanistically, DDX3X represses the expression of stemness genes via upregulation of the expression of a subset of tumour-suppressive miRNAs, including miR-200b, miR-200c, miR-122 and miR-145, by reducing DNMT3A (DNA methyltransferase 3A) binding and hypermethylation on their promoter regions [66] (Fig. 8a).