RB1 and retinoblastoma: Although p53 mutations are infrequent in human retinoblastomas, the p53 pathway may be intrinsically attenuated upon RB1 loss by miR-24-mediated downregulation of p14ARF (To et al., 2012) and by NANOS-mediated suppression of p53-activating kinases (Miles et al., 2014).