Cell surface glycoprotein that plays a role in cell adhesion, intracellular signaling and tumor progression (PubMed:2803308, PubMed:10910050, PubMed:10864933). Mediates homophilic and heterophilic cell adhesion with other carcinoembryonic antigen-related cell adhesion molecules, such as CEACAM6 (PubMed:2803308). Plays a role as an oncogene by promoting tumor progression; induces resistance to anoikis of colorectal carcinoma cells (PubMed:10910050). (Microbial infection) Receptor for E.coli Dr adhesins. Binding of E.coli Dr adhesins leads to dissociation of the homodimer. Homodimer. Localized to the apical glycocalyx surface. Expressed in columnar epithelial and goblet cells of the colon (at protein level) (PubMed:10436421). Found in adenocarcinomas of endodermally derived digestive system epithelium and fetal colon. Complex immunoreactive glycoprotein with a MW of 180 kDa comprising 60% carbohydrate. Belongs to the immunoglobulin superfamily. CEA family.