These data indicate that targeted STAT3 deletion inMDSCs leads to uncontrolled T cell activation and initiates intestinal inflammation.Here, we show that the expansion of G-MDSCs in the colon ofLysMcre/STAT3flox mice is reduced during acute and chronicDSS-induced colitis and that the secretion of anti-inflammatory Th2 cell cytokines(IL-4, IL-10, IL-13) by MDSCs of LysMcre/STAT3flox mice issuppressed. The gene discussed is IL4; the disease is colitis.