(A) Representative colon gross anatomy of WT and STAT1 KO mice. (B) Representative histology of WT and STAT1 KO colons, stained with H&E (scale bar = 200 μm). (C) Histopathologic scores of WT and STAT1 KO colons. Scoring was performed for severity and extent of inflammatory cell infiltrates and for epithelial changes (hyperplasia [hyperpl] and goblet cell loss [GC loss]) (n = 5 for WT, n = 6 for STAT1 KO) *p<0.05, **p<0.01 by Mann−Whitney U test. (D) Bacterial leakage (CFU/organ) into liver (LIV), mesenteric lymph nodes (MLN) and spleen (SPL), as described in materials and methods (n = 5 for WT, n = 7 for STAT1 KO). (E) Colon length after 7 days of DSS treatment in drinking water (n = 4 for WT, n = 7 for STAT1 KO) **p<0.01 by Student’s t-test. (F) Representative histology of WT and STAT1 KO colons, stained with H&E, after 7 days of DSS treatment (scale bar = 200 μm). Each symbol represents an individual animal (C–E).