PTBP1 and breast cancer: RoR disrupts p53-mediated cell cycle arrest and apoptosis via an autoregulatory feedback loop where p53 transcriptionally induces RoR expression, and in turn, RoR inhibits p53 translation through hnRNP I. This RoR-hnRNP I-p53 axis may constitute an additional surveillance mechanism for cells in breast cancer (63).