CEACAM3 encodes a member of the family of carcinoembryonic antigen-related cell adhesion molecules (CEACAMs), which are used by several bacterial pathogens to bind and invade host cells. Carcinoembryonic Antigen Related Cell Adhesion Molecule 3 directs phagocytosis of several bacterial species that is dependent on the small GTPase Rac. It is thought to serve an important role in controlling human-specific pathogens by the innate immune system. Alternatively spliced transcript variants have been described.