Contactin-2 is also known as CNTN2, TAX1 (transiently-expressed axonal glycoprotein), TAG1 (transient axonal glycoprotein), and axonin-1, and is a member of the immunoglobulin superfamily. CNTN2 consists of six Ig-like domains and four fibronectin type III domains, and is anchored to the membrane by glycosylphosphatidylinositol (GPI), whereas the soluble form can be released by a GPI-specific phospholipase. As a neural cell adhesion molecule expressed by a subset of neuronal populations in the developing CNS and PNS, CNTN2 mediates cell-cell interactions either via homophilic, or heterophilic contacts with various adhesion molecules including NgCAM, NrCAM, NCAM and neurocan. 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. It may also be involved in glial tumorigenesis and may provide a potential target for therapeutic intervention.