Extracellular Crosstalk: When GDNF Meets N-CAM

N-CAM has now been identified as a receptor for glial cell line-derived neurotrophic factor (GDNF). This finding solves a long-standing question regarding RET-independent GDNF signaling, and reveals a novel pathway distinct from both GDNF–RET and N-CAM–N-CAM signaling. Functional assays of Schwann cell migration and axon growth of CNS neurons suggest physiological significance for this GDNF–N-CAM pathway.