Nerve growth factor (NGF) is important for the development , differentation, and survival of a variety of neuronal and non-neuronal cells. NGF action is mediated by binding to two distinct receptors, the high affinity p140 and low affinity p75 NGF receptors. P75NGFR binds neurotrophins including brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), neurotrophin 4/5 (NT-4/5) and NT-6. p75NGFR belongs to the TNF-R superfamily reported to mediate NGF-induced apoptosis. Defects in NGF are the cause of hereditary sensory and autonomic neuropathies.