Fig. S6 shows that endogenous IL-4 and IFN-γ do not effect Foxp3 expression in naive CD4+ T cells of CbfbF/F CD4-cre and CbfbF/F control mice, which were stimulated with anti-CD3 and anti-CD28 mAbs, IL-2 and TGF-β in the absence or presence of anti-IL-4 and anti-IFN-γ neutralizing mAbs.