MUC5AC and neoplasm: That mucinous carcinoma of the ovary, gastro-intestinal, and bilio-pancreatic neoplasms showed co-expression of TFF1 and MUC5AC (20% to 53%) more commonly than other tumor entities is in line with some previous studies describing high rates of MUC5AC/TFF1 co-expression in neoplasms of the colon, liver, stomach, and gallbladder [8,18,61,62].