TP53 and neoplasm: Further support for the paradigm of a universal mechanism of action for p53 in mammalian cancer came from the finding that humans with germline mutations in TP53 experience an inordinately high risk of a wide array of tumor types before the age of 30 years (Varley 2003, Guha & Malkin 2017) and that inactivation of p53 in the so-called p53-knockout mouse duplicates this high risk of a wide array of tumor types occurring at an early age (Lozano & Liu 1998, Kenzelmann Broz & Attardi 2010).