Trefoil factor 3 is a protein that in humans is encoded by the TFF3gene.
Members of the trefoil family are characterized by having at least one copy of the trefoil motif, a 40-amino acid domain that contains three conserved disulfides. They are stable secretory proteins expressed in gastrointestinal mucosa. Their functions are not defined, but they may protect the mucosa from insults, stabilize the mucus layer and affect healing of the epithelium. This gene is expressed in goblet cells of the intestines and colon. This gene and two other related trefoil family member genes are found in a cluster on chromosome 21.
A process using an ingestible oesophageal sampling device (Cytosponge) coupled with immunocytochemisty for trefoil factor 3 to improve the accuracy and acceptability of the detection/screening of Barrett's oesophagus has been developed.