- hP1.B, a human P-domain peptide homologous with rat intestinal trefoil factor, is expressed also in the ulcer-associated cell lineage and the uterus. Hauser, F., Poulsom, R., Chinery, R., Rogers, L.A., Hanby, A.M., Wright, N.A., Hoffmann, W. Proc. Natl. Acad. Sci. U.S.A. (1993)