Clone REA428 recognizes an epitope shared by the human CD66a, c, d, and e antigens, which are also known as the human carcinoembryonic antigen (CEA) family. The CEA family has 7 genes belonging to the CEACAM subgroup. These subgroup members are mainly associated with the cell membrane and show a complex expression pattern in normal and cancerous tissues. CD66a (CEACAM1) is an adhesion molecule that is involved in many immune responses associated with infection, inflammation, and cancer. It interacts homophilically with CD66a and heterophilically with CD66e (CEACAM5), but not with other CEACAM proteins. CD66a is expressed on a variety of cells, e.g., some epithelial cells, melanoma, and activated lymphocytes. Within the hematopoietic system, CD66c (CEACAM6) expression is limited to granulocytes and its precursors, where it serves homotypic and heterotypic adhesion and Ca2⁺ mediated signaling. It is markedly upregulated from intracellular stores after activatio and is also found in epithelia of various organs. CD66c overexpression is found in a wide variety of epithelial cancer types such as lung, breast, colorectal, and hepatocellular carcinomas. CD66d (CEACAM3) is a major granulocyte receptor mediating recognition and efficient opsonin-independent phagocytosis of CEACAM-binding microorganisms, thus playing an important role in the clearance of pathogens by the innate immune system. CD66e (CEACAM5) plays a role in cell adhesion and in intracellular signaling. It is known to be overexpressed in a majority of carcinomas, including those of the gastrointestinal tract, the respiratory and genitourinary systems, and breast cancer.

Additional information: Clone REA428 displays negligible binding to Fc receptors.

Alternative names

BGP-1, CEACAM5, CEACAM3, CEACAM6, BGP-1, CGM1, NCA, CEA, CEACAM1

Technical specifications