CD4 and colitis: In our study, CD4+ T cell depletion did not show obvious effect on DSS-induced colitis in WT mice, but it effectively reduced symptoms of colitis as well as colonic expression of Th17 and Th1 cytokines in mPGES-1−/− mice, suggesting the requirement of CD4+ T cells in the exacerbation of DSS-induced colitis under mPGES-1 deficiency.