CEACAM5 and neoplasm: The diagnosis of biliopancreatic cancer is based on a combination of medical history and physical examination, serum tumor marker levels (i.e., CA19-9: carbohydrate antigen 19-9; CEA: carcinoembryonic antigen), imaging techniques (i.e., US: ultrasonography; EUS: endoscopic ultrasound; ERCP: endoscopic retrograde cholangiopancreatography; CT: computed tomography; MR: magnetic resonance), and pathological confirmation of tissue specimens.