IRF-4 deficiency accelerates disease progression in a BCR/ABL-induced B-ALL mouse model. (A) Number of GFP⁺ cells in peripheral blood of mice reconstituted with IRF-4 KO BM infected with BCR/ABL-IRES-GFP is significantly higher than the number of GFP⁺ cells from mice reconstituted with IRF-4 Het BM infected with BCR/ABL-IRES-GFP (P = .03). There were 9 mice in each group, and all mice were used to obtain these results. (B) Survival of mice receiving transplantation of IRF-4 Het or IRF-4 KO bone marrow cells infected with BCR/ABL-GFP– or GFP-containing retroviruses. Survival curves were generated by Kaplan-Meier survival analysis. Statistical analysis of survival data were performed with StatView 5 (Abacus Concepts) using the Kaplan-Meier survival analysis and Mantel-Cox (log-rank) test functions.