Both imaging techniques and serological markers, such as carbohydrate antigen 19-9 (CA19-9) and carcinoembryonic antigen (CEA), have used for many years for diagnosis of PDAC, however, it is still difficult to distinguish patients with chronic pancreatitis (CP), a high-risk population for PDAC, from those with PDAC [6–9]. Here, CEACAM5 is linked to chronic pancreatitis.