Upon necropsy 15/28 (54%), Ptpn2fl/fl;p53+/− mice developed various tumours including thymomas, lymphomas, sarcomas, carcinomas and hepatomas (Fig 1A; Appendix Fig S1; Appendix Table EV1) as reported previously for p53 heterozygous mice (Jacks et al, 1994). The gene discussed is TP53; the disease is hepatocellular carcinoma.