This marker is not expressed in normal pancreas but is expressed by most pancreatic ductal adenocarcinomas. MUC5AC is expressed also by endocervical adenocarcinomas and a variable number of tumors of the gastrointestinal tract. Together in a panel of antibodies, MUC5AC may be useful for identification of pancreatic carcinoma and pre-cancerous changes and differentiation of intestinal metaplasia.