For example, caspase-2 deficiency enhances lymphomagenesis in Eμ-Myc transgenic mice that develop B-cell lymphoma9, 10 and in ataxia telangiectasia mutated (Atm)-deficient mice that spontaneusly develop thymic lymphoma.11 Furthermore, MMTV/c-neu-driven mammary carcinoma,12 K-Ras-driven lung carcinoma13 and diethylnitrosamine-mediated hepatocellular carcinoma14 also show more rapid develoment of tumours in caspase-2-deficient (Casp2−/−) mice. The gene discussed is ATM; the disease is breast carcinoma.