Rag1−/− mice receiving CD4+ CD45Rbhi T cells alone developed severe colitis, as evidenced by increased weight loss (Figure 1C), higher pathological scores (Figure 1D,E), and intestinal TNF‐α and IL‐6 levels (Figure 1F,G), which were inhibited by co‐transfer of WT or miR‐10a‐deficient Tregs. Here, IL6 is linked to colitis.