As routine screening programs for CRC, non-invasive methods such as fecal occult blood testing (FOBT) and carcinoembryonic antigen (CEA) testing, and invasive methods such as high-quality colonoscopy can reduce the risk of death from CRC to some extent (Medical Advisory Secretariat, 2009; Forones & Tanaka, 1999; Waldmann et al., 2021). Here, CEACAM5 is linked to colorectal carcinoma.