STAT3 and graft versus host disease: In fact, treatment with a small molecule that inhibits STAT3 phosphorylation (22) or transplantation with STAT3-deficient T cells (21) significantly reduced GVHD-related mortality and pathological damage within the colon, providing support for the premise that STAT3-depednent cytokines play a prominent role in the induction of inflammation within this tissue site.