The Low-Affinity Nerve Growth Factor Receptor (also called the LNGFR or p75 neurotrophin receptor) is one of the two receptor types for the neurotrophins, a family of protein growth factors that stimulate neuronal cells to survive and differentiate. The precise function of the LNGFR is somewhat controversial, in contrast to the function of the high-affinity receptor family for the neurotrophins, the Trk receptor tyrosine kinases such as TrkA.