The protein encoded by this gene is a member of the immunoglobulin superfamily. It is a glycosylphosphatidylinositol (GPI)-anchored neuronal membrane protein that functions as a cell adhesion molecule. It may play a role in the formation of axon connections in the developing nervous system. Two alternatively spliced transcript variants encoding different isoforms have been described for this gene. Synonyms: Polyclonal CNTN1 antibody, Anti-CNTN1 antibody, contactin 1 antibody, F3 antibody, GP135 antibody.