The trefoil factorfamily (TFF) comprises three disulfide-richpeptides (TFF1, TFF2, TFF3) that are abundantly secreted in the gastrointestinaltract where they regulate gut homeostasis by promoting gut protectionand repair.1−5 They are also expressed in mucosal tissues outside the gut, includingin the respiratory tract, urinary tract, uterus, eyes, and salivaryglands, where they have similar mucosal repair and protective functions.TFF peptides have also been observed in human breast milk and thebrain,1,6,7 and have beenimplicated in cancer development.1,8,9. Here, TFF3 is linked to cancer.