In a SCID mouse model of colitis, feeding SEB to mice reconstituted with CD4+CD45RBhigh T cells resulted in an earlier onset of intestinal inflammation and more severe symptoms, which was accompanied by activation and expansion of SEB-reactive CD4+Vβ8+ T cells and marked impairment in CD4+CD25+Foxp3+ Treg cell development . Here, CD4 is linked to colitis.