CEACAM5 and metastatic malignant neoplasm: Currently applied tumor markers carbohydrate antigen 19-9 (CA 19-9) and carcinoembryonic antigen (CEA) have limited diagnostic value because of their low sensitivity and specificity for BTCs.2,3,4 CA 19-9 tends to have higher specificity than CEA (92.7% vs. 79.2%, respectively); however, its sensitivity tends to be lower (50% vs. 79.4%, respectively).2,3,4 Moreover, they are not specific for gallbladder cancer and can also be significantly elevated in benign diseases of the liver or in other metastatic cancers.