Medical Dictionary Online

Trefoil Factors

A family of small peptides expressed primarily by MUCOUS MEMBRANE EPITHELIAL CELLS in vertebrates. Their structure is highly conserved and is defined by a three-leaved (trefoil) domain of 42 or 43 amino acids; it includes six cysteines that create the trefoil structure through disulfide bridges. Trefoil peptides may form dimers with each other, or associate with MUCINS and other factors. They are important for maintaining epithelial integrity and for protection from noxious agents.