In this model the transfer of colitogenic naïve CD4+ T cells specific for the immunodominant commensal antigen, CBir1 flagellin (CBir-1Tg) but not of naïve CD4+ T cells from OTII mice which do not induce colitis in immune-deficient TCRb/d−/− mice was associated to the generation of IFNγ-expressing Th1-like Tregs. This evidence concerns the gene CD4 and colitis.