CD4 and colitis: However, using the T cell-transfer model of colitis, we showed that adoptive transfer of Smad7 Tg naïve CD4+ T cells into immunodeficient mice produced a more severe intestinal inflammation than that documented in mice reconstituted with wild-type cells, and colitis induced by Smad7 Tg cells was only partly inhibited by co-transfer of Tregs (75).