MDM2 and breast carcinoma: A recent study showed that 5S ribonucleoprotein particle (5S RNP)‐mediated p53 activation coupled perturbed ribosomal biogenesis with cell proliferation and cell cycle regulation.21 Furthermore, the tumour‐suppressive role of the 5S RNP‐p53 pathway through either MDM2 interaction or Hdm‐p53 checkpoint regulation has been widely studied in cancer.26, 27 We thus hypothesize that the 5S RNP‐p53 pathway plays an important role in the proliferation of breast cancer upon RRS1 knockdown.