In order to address the lack of a model with relevance to the anti-TNFα non-responding UC patient group we planned to develop a viable model based on the best recently described murine model of UC currently available, namely Winnie. Winnie colitis is due to a missense mutation in the Muc2 mucin gene19 resulting in spontaneous distal colitis developing as early as 5 weeks of age. Here, MUC5AC is linked to colitis.