β-NGF is a pluripotent mediator and it exists in many tissues. Secreted β-NGF can bind to tryosine kinase A receptor with higher affinity and to p75 (NTR) with low affinity. β-NGF is well known as an endogenous neurotrophic factor involved in the embryonal development, survival, and regeneration of mammalian sympathetic and sensory neurons. In adults, β-NGF is also involved in the survival and regeneration of neurons in the central nervous system. Involvement of β-NGF in the immune system has also been reported. In vitro cultured B lymphocyte can constitutively secret β-NGF, which can act as an autocrine growth and differentiation factor for B cells. β-NGF can also downregulate the production of IFN-γ by T cells. Recombinant β-NGF has been used in many clinical trials to treat different disease including Alzheimer's disease, diabetic polyneuropathy, and HIV-associated peripheral neuropathy.?