RAG1-S723C/p53 double-mutant mice are predisposed to thymic lymphomas with chromosomal translocations. (A) Survival of a cohort of control (RAG1^+/+, RAG1^+/S723C, RAG1^S723C/S723C, n = 39), p53^−/− (RAG1^+/+p53^−/−, RAG1^+/S723Cp53^−/−, n = 35), and RAG1^S723C/S723Cp53^−/− (n = 31) mice was observed for a period of 35 weeks. Kaplan-Meier survival curves were compared using the 2-tailed log-rank test with a 95% confidence interval (RAG1^S723C/S723Cp53^−/− vs p53^−/− cohorts, P = .017; RAG1^S723C/S723Cp53^−/− vs control cohorts, P < .001). (B) RAG1^S723C/S723Cp53^−/− thymic lymphomas harbor chromosomal translocations and fusions. DAPI staining (left panels) and SKY analysis (right panels) of tumors S542 and S922 containing clonal chr 15;15 and 12;12 short-arm fusions and t(14;8) translocations, respectively. Arrows indicate translocated chromosomes.