(Science: protein) a 130 kd glycoprotein attached to the cytoskeleton via its cytoplasmic domain, concentrated in areas of interneuronal contact. Its sequence contains both immunoglobulin like domains and fibronectin type III repeats. Its close homology with N cam suggests that it is a cam. Like L1, F11, neurofascin and tag 1 in vertebrate nervous systems and fasciclin II in insects, thought to be associated with the process of selective fasciculation. Sometimes gpi linked.