Trefoil factor (TFF) peptides are family of small regulatory proteins consisting of three members [4], TFF1 (pS2) [3, 5], originally identified as an estrogen-responsive gene in the MCF-7 human breast cancer cell line, Spasmolytic polypeptide, TFF2 (SP) [3, 6], and intestinal trefoil factor, TFF3 (ITF) [3, 7]. Here, TFF3 is linked to breast cancer.