CCND1 and cancer: A recent article reports that overexpression of miR-33a or miR-33b induces a significant G1 arrest in cancer cell lines through targeting the cyclin-dependent kinase 6 (CDK6) and cyclin D1 (CCND1) genes (Cirera-Salinas et al, 2012), supporting that the miR-33 family is a regulator of cell cycle progression both directly (targeting CDK6 and CCND1) and indirectly (targeting c-Myc to reduce cyclin E expression).