NCAM was identified as an alternative signaling receptor for GDNF family ligands (GFLs). The GFLs is a small group of soluble neurotrophic growth factors involved in neuronal survival, neurite growth and differentiation. Four members are known in the family including GDNF, Neurturin (NTN), Persephin (PSP), and Artemin (ART). NCAM, in collaboration with GFR? receptors, function as a signaling receptor for these GFLs. Signaling downstream of GDNF binding to the NCAM-GFRalpha1 complex activates Fyn-FAK-MAPK signaling pathway and mediates long-range intercellular communication.