MUC5AC and familial pancreatic carcinoma: In pancreas, mucins are secreted by pancreatic duct cells.22 It has been reported that mucin gene is abnormally expressed in pancreatic cancer and may have opportunities to play a role in the diagnosis and therapy.23 CA 19‐9, CA 242, and CA 50 are mucin markers and are thought to be aberrantly expressed when patients are suffering from pancreatic cancer.