As our data indicate that WT mice with adoptive transferring of MDSCs (Figure 5A) displayed a lower serum IL-17 level compared to WT mice in DSS-colitis, we hypothesize that MDSCs, which are expanded in PTP1B−/− mice, may suppress the frequencies of IL-17–secreting Th17 cells. This evidence concerns the gene PTPN1 and colitis.