ALCAM ( Activated Leukocyte Cell Adhesion Molecule ) / CD166 is a member of a small sub-group of transmembrane glycoproteins belonging to the immunoglobulin superfamily . The fully formed protein assigned to this group are characterized by the presence of three fragments : the extracellular międzybłonowego and a short cytoplasmic region . ALCAM/CD166 participates in heterophile ( ALCAM/CD166-CD6 ) and homofilnej ( ALCAM/CD166-ALCAM/CD166 ) in a variety of cell adhesion tissues and cell lines .