SIRT1 and cancer: Indeed miR-34a acts as a tumor suppressor through the downregulation of many target genes in cancer cells, including NAD-dependent deacetylase sirtuin-1 (SIRT1), hepatocyte growth factor receptor c-MET, cyclin-dependent kinase 6 (CDK6), B-cell lymphoma 2 (BCL2), and cell surface glycoprotein CD4417, 18, 19, 20, 21.