CD4 and colitis: While RAG-deficient (RAG2−/−) recipients of CD4+ T cells suffered from severe colitis with weight loss and high-grade intestinal inflammation (Figure 2K; Figures S3A,B,C in Supplementary Material), co-transfer of Keap-deficient CD11b+Gr-1+ cells markedly reduced loss of weight and intestinal inflammation (Figure 2K; Figures S3B,C in Supplementary Material).