Despite several traditional blood-based biomarkers, including carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), and carbohydrate antigen 72-4 (CA72-4), have been widely applied in suggesting the presence of gastrointestinal tumors (Xu et al, 2023), they were inappropriate for the early screening of GC owing to their low sensitivities (Sekiguchi and Matsuda, 2020). Here, CEACAM5 is linked to digestive system neoplasm.