His conventional tumor markers were within the normal range: carcinoembryonic antigen (CEA) was 1.2 ng/mL (normal range: below 5.0 ng/mL) and carbohydrate antigen (CA) 19–9 was 3.6 U/mL (normal range: below 37.0 U/mL). Here, CEACAM5 is linked to neoplasm.