MET inactivation in ENS precursors increased mucosal injury in response to DSS treatment. A–F, Metfl/fl; Wnt1Cre+ mice and Metfl/fl; Wnt1Cre control animals were treated with 2.5% DSS in drinking water for 14 d and then examined using a dissecting microscope (A, B) or after paraffin sectioning and hematoxylin and eosin staining (C, D). E, F, Quantitative analysis of ulcer area in the descending colon and ulcer length in the rectum demonstrated increased ulcers in Metf/f; Wnt1Cre+ mice compared with controls. *p < 0.01, Student's t test. G, Kaplan–Meier analysis demonstrated that DSS-treated Metfl/fl; Wnt1Cre+ mice had higher death rates than controls (N = 8 Met cKO and 11 control mice). p < 0.05, log-rank test. H–J, BrdU labeling after 7 d of DSS treatment showed reduced colonic epithelial cell proliferation within crypts of Metf/f; Wnt1Cre mice compared with control animals. *p < 0.01, Student's t test. Yellow arrows: ulcerated regions (N = 5 Met cKO and 4 control animals/group for ulcer analysis and BrdU labeling).