FOXP3 and Crohn ileitis: Whereas in WT mice a significant, approximately two-fold influx of FOXP3+ regulatory T cells (Treg) into the small intestinal mucosa could be observed at day 7 p.i. (p<0.001 vs naïve control mice; Fig. 2E and Fig. S6), Treg numbers were significantly lower in NOD2-/- mice following ileitis induction (p<0.05; Fig. 2E and Fig. S6) and did not differ compared to uninfected, naïve NOD2-/- animals.