BATF KO T cells are defective in inducing colitis. Rag1^−/− mice were injected with the naive CD4⁺CD25⁻ T cells isolated from WT or BATF KO mice. (A) Weight change after injection of WT or BATF KO naive CD4⁺CD25⁻ T cells was monitored. (B) Histological changes of the intestine of Rag1^−/− mice injected with naive CD4⁺CD25⁻ T cells were examined at the time of mouse termination. Bars, 200 µm. (C) Frequencies of Th1, Th17, and FoxP3⁺ T cells in Rag1^−/− mice injected with naive CD4⁺CD25⁻ T cells were determined by flow cytometry. Pooled data obtained from three experiments are shown in the graphs (n ≥ 10/group). All error bars are SEM obtained from pooled data. Significant differences between indicated groups or from WT groups are shown (*, P < 0.05).