Although the recipient Rag1−/− mice reconstituted with CD4+ CD45Rbhi T cells and Blimp1‐deficient Tregs developed less severe colitis compared with that reconstituted with CD4+ CD45Rbhi T cells alone, they displayed more severe colitis compared to the mice receiving CD4+ CD45Rbhi T cells and WT Tregs, as evidenced by increased weight loss, higher pathological scores, and elevated levels of intestinal TNFα and IL‐6 (Figure 4D–H). This evidence concerns the gene CD4 and colitis.