Dysplasia scores in Smad3−/− mice correlated with IBD scores (Spearman’s r = 0.8904, P<0.001) and were significantly higher (P = 0.0176) than dysplasia scores in Smad3+/− mice (mean dysplasia score = 5.7 vs. 0.71). This evidence concerns the gene SMAD3 and inflammatory bowel disease.