Several independent prognostic factors for CCA have been identified, including serum carcinoembryonic antigen (CEA) levels, alkaline phosphatase levels, relapse of disease, intraoperative blood transfusion, lymph node metastasis, TNM staging [6, 7], histological differentiation of tumors, surgical margins, types of CCA, Caudal Type Homeobox 2 (CDX2), and human epidermal growth factor receptor 2 (HER2) gene amplification [8]. Here, CEACAM5 is linked to cholangiocarcinoma.