CNTNAP3 belongs to the NCP family of cell-recognition molecules. This family represents a distinct subgroup of the neurexins. NCP proteins mediate neuron-glial interactions in vertebrates and glial-glial contact in invertebrates. The protein encoded by this gene may play a role in cell recognition within the nervous system. Alternatively spliced transcript variants encoding different isoforms have been described but their biological nature has not been determined.The deduced 1,288-amino acid protein contains a large extracellular N-terminal domain, a single membrane-spanning domain, and a short C-terminal cytoplasmic region. The extracellular domain contains discoidin and fibrinogen-like domains, 2 EGF-like repeats, and 4 laminin G (LNS) domains that comprise a globular lectin-like fold; the C terminus ends in a PDZ domain-binding site.