Recombinant mice carrying one or two inactivated Fhit alleles are viable and long-lived but show increased rates of spontaneous and carcinogen-induced cancers (Fong et al, 2000; Zanesi et al, 2001); thus, Fhit-deficient mice are excellent models for preclinical studies of tumour development, prevention and therapy. The gene discussed is FHIT; the disease is cancer.