Collagen triple helix repeat-containing protein 1 is a protein that in humans is encoded by the CTHRC1 gene. It acts as a negative regulator of collagen matrix deposition. It may cause the disease of Barrett esophagus . Patients with Barrett esophagus have an increased risk of esophageal adenocarcinoma. The main cause of Barrett esophagus is gastroesophageal reflux. The retrograde movement of acid and bile salts from the stomach into the esophagus causes prolonged injury to the esophageal epithelium and induces chronic esophagitis, which in turn is believed to trigger the pathologic changes.