Interestingly, 100% Brca1−/−;Trp53bp1−/− mice succumbed to thymic lymphoma within 7 months while none of the Trp53bp1−/− mice in the cohort were dead during this period (Fig. 4a, b), which is a stronger phenotype than that observed in Brca1ΔC/ΔC;Trp53bp1−/− mice. The gene discussed is BRCA1; the disease is thymus lymphoma.