DNMT1 and cancer: The downstream targets of piRNA-823 include DNA methyltransferases (DNMTs) genes as DNMT1, DNMT3A, and DNMT3B which maintain methylation of DNA leading to regulation of gene expression, DNMTs gene expression is increased by piR-823, which encouraged adenomatous polyposis coli (APC) gene methylation thus causing Wnt signaling activation and provoking cancer cell stemness, on the other hand piRNA-823 was proved to promote carcinogenesis by regulating cancer stem cells [46].