Establishment of the CXP B cell lymphoma model via conditional inactivation of Xrcc4 in CD21Cre-expressing, p53-deficient mice. (A) Kaplan-Meier survival curve: percent survival of CXc/−P−/− (n = 24); CXc/−P+/− (n = 25); CP−/− (n = 15); and CXc/− (n = 25) mice versus age in days is shown. (B) Tumor types that developed in the indicated cohorts of CXc/−P−/− and CP−/− mice. The number of mice that developed a given type of tumor is indicated at the left. Deletion of the floxed Xrcc4 allele in given tumors is indicated at the right. nd, not determined; N/A, not applicable. The asterisk indicates CXc/−P−/− mice that developed osteosarcoma or thymic lymphomas, in addition to B cell lymphomas.