Nerve growth factor (NGF), located on chromosome 1p13.1 [85], is a member of the neurotrophin family and it consists of three subunits: alpha, beta, and gamma [94]. The beta subunit (NGFB), which is hypothesized to be the only subunit responsible for the biological activity of NGF, modulates the development and signaling of the nervous system via a testosterone-regulated process [94].
