The Trefoil Factor peptides (TFF1, TFF2 and TFF3) are expressed in the gastrointestinal tract, and appear to play an important role in intestinal mucosal defense and repair. TFF1 is essential for normal differentiation of the antral and pyloric gastric mucosa and functions as a gastric-specific tumor suppressor gene. Recombinant human TFF1 is a 6.7 kDa monomeric protein consisting of a 60 amino acid polypeptide chain, which includes a 40-amino acid trefoil motif containing three conserved intramolecular disulfide bonds.