Human gastrointestinal tract mucins encoded by the MUC gene family

Epithelial mucins, MUC gene products, are widely expressed in human organs such as airways, the urogenital and gastrointestinal tracts, and the eyes. MUC-type mucins have very large sizes and complex structures with very extensive O-glycosylation and are regarded as protective molecules. The aim of this review is to discuss mucin glycoproteins structure, biosynthesis and functions in normal and pathologically altered epithelial mucosa of human gastrointestinal tract.