Human CNTF Recombinant Protein. Ciliary Neurotrophic Factor (CNTF) is a neurotrophic factor that promotes the survival of various neuronal cell types and may play an important role in the injury response in the nervous system. CNTF, like FGF acidic, FGF basic, and PD-ECGF (platelet-derived endothelial cell growth factor), does not possess a signal sequence that would allow secretion of the factor by classical secretion pathways (endoplasmatic reticulumGolgi system), but the mechanism underlying the release of CNTF is unknown.