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nerve growth factor n a protein that promotes development of the sensory and sympathetic nervous systems and is required for maintenance of sympathetic neurons abbr. NGF
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(NGF) a neurotrophin, secreted by a wide variety of cells, that regulates the proliferation, differentiation, and survival of sympathetic and sensory neurons; it is also involved in the initiation of pain and is a mediator of inflammation, particularly in the airways. It was originally discovered as a high-molecular-weight complex consisting of α, β, and γ subunits; the active form in humans is the β dimer.Medical dictionary. 2011.