Since it has been reported that IFNγ KO mice are protected from DSS-induced colitis (18), we examined whether dysregulated IFNγ expression in heterozygous Yeti mice, in which abnormal IFNγ secretion occurs due to modification of the 3′-untranslated region (UTR) of the IFNγ gene (16), influences colitis severity. This evidence concerns the gene IFNG and colitis.