Used in cancer immunotherapy research, particularly targeting colorectal, gastric, and pancreatic cancers. Serves as a recombinant antigen source for developing monoclonal antibodies, diagnostic assays, and CAR-T cell therapies. Supports validation of CEACAM5-specific binding agents and evaluation of immune responses in preclinical models. Expressed in HEK293 cells for proper post-translational modification, enhancing its biological relevance in functional studies and therapeutic screening.