FOXP3 and colitis: In line with our results in Il10−/−Mdr2−/− mice, colitis severity and CD4+ T-cell infiltration in the inflamed colon of Il10−/− mice was attenuated under the DDC diet (figure 2B), and frequencies of colonic Foxp3+ Treg cells were increased compared with the regular chow diet (figure 2C,D).