The p53 tumor suppressor protein is a key factor in the cellular stress response.1, 2 Functional p53 prevents the progression of cancer by mounting growth inhibition in the form of apoptosis, senescence and/or autophagy.3 The exact tumor suppressive functions of p53 that prevent cancer are currently the subject of extensive studies (reviewed in Bieging et al.4). The gene discussed is TP53; the disease is cancer.