Staging of biliary tract tumors includes CT or MRI scans with intravenous contrast, a chest CT, liver function tests, serum carcinoembryonic antigen (CEA), cancer antigen 19–9 (CA 19–9), and AFP levels, a hepatitis panel, biopsy and esophagogastroduodenoscopy, and colonoscopy, in the case of ICC. This evidence concerns the gene CEACAM5 and intrahepatic cholangiocarcinoma.