Spontaneous CLL development in IRF4-deficient Vh11 knock-in mice. (A) Kaplan-Meier Event-free survival curve of IRF4^+/+Vh11, IRF4^+/−Vh11, and IRF4^−/−Vh11 mice. Twelve mice from each genotype were used for the analysis. P values are pairwise comparison (log-rank test) between IRF4^+/+Vh11 and IRF4^+/−Vh11, and between IRF4^+/+Vh11 and IRF4^−/−Vh11. Graphpad PRISM was used to plot the survival curve and to calculate P value. (B) Kaplan-Meier overall survival curve of IRF4^+/+Vh11 and IRF4^−/−Vh11 mice. Ten mice from each genotype were used for the analysis. (C) Cells were isolated from blood, PC, bone marrow, lymph node, and spleen of 5-month-old IRF4^+/+ Vh11 and IRF4^−/−Vh11 mice. The isolated cells were stained with antibodies against CD5 and IgM and analyzed by FACS. (D) Blood was collected from IRF4^+/+Vh11, IRF4^+/−Vh11, and IRF4^−/−Vh11 mice for FACS analysis. The blood was collected from these mice every 2 months for a period of 8 months. There were 5 mice in each group. The frequency of CD5⁺IgM⁺ cells among PBMCs was calculated by FACS analysis. The average and SD of the frequency of CD5⁺IgM⁺ cells in each group at different time points were calculated (top). A representative FACS analysis for each group at different time points was shown (bottom). BL, blood; BM, bone marrow; LN, lymph node; SPL, spleen.