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. Here, CEACAM5 is linked to gallbladder cancer.