NTF5 is a member of a family of neurotrophic factors, neurotrophins, that control survival and differentiation of mammalian neurons. While knock-outs of other neurotrophins including nerve growth factor, brain-derived neurotrophic factor, and neurotrophin 3 prove lethal during early postnatal development, NTF5-deficient mice only show minor cellular deficits and develop normally to adulthood.