Although serum markers for PDAC including carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) play important roles in current clinical practice for monitoring progression and treatment response, as well as surveillance for recurrence, these markers are not ideal for cancer screening due to their low specificity and/or sensitivity in early stages of the disease [4–6]. This evidence concerns the gene CEACAM5 and cancer.