CCND1 and neoplasm: It has been documented that transfection of miR-34a induces cell cycle arrest in immortalized mouse cells and in human tumor cell lines and sensitizes to apoptosis in response to genotoxic stress [14, 96], which is consistent with the observed ability of miR-34a to downregulate genes promoting cell cycle including Cyclin E2, Cyclin D1, CDK4, CDK6, E2F1, E2F3, E2F5, and SIRT1 [14, 98].