TP53 and retinoblastoma: Given that the other cell lines tested display different genetic or protein changes to those seen in retinoblastoma cell lines, such as wild-type RB1 (SKOV3 and OVCAR3), inactivated pRb (HeLa and HEK-T) or mutant TP53 (SKOV3, OVCAR3 and SaOS2) [29,30], further investigation into the functional mechanisms of ARF regulation via miR-24 are required.