- Barrett's esophagus is characterized by expression of gastric-type mucins (MUC5AC, MUC6) and TFF peptides (TFF1 and TFF2), but the risk of carcinoma development may be indicated by the intestinal-type mucin, MUC2. Warson, C., Van De Bovenkamp, J.H., Korteland-Van Male, A.M., Büller, H.A., Einerhand, A.W., Ectors, N.L., Dekker, J. Hum. Pathol. (2002)