The major intestinal transmembrane mucins, MUC1, MUC3 (murine orthologue Muc17), MUC4 and MUC13, are intercalated into the apical surface of the intestinal epithelium and contribute to the glycocalyx layer.12, 22 However, the focus of this review will be the major component of the intestinal mucus gel, the secreted polymeric mucin, MUC2.23 It is noteworthy that MUC5AC expression can be induced within the intestine during foetal development, adenocarcinoma inflammatory bowel disease, and of specific relevance to this review, during helminth infection.9, 24, 25, 26. The gene discussed is MUC5AC; the disease is inflammatory bowel disease.