Ciliary Neurotrophic Factor (CNTF) is a neurotrophic cytokine that belongs to the interleukin-6 (IL-6) family of cytokines. It was initially discovered in the chick ciliary ganglion, a collection of neurons associated with the parasympathetic nervous system. CNTF plays a crucial role in the survival, differentiation, and maintenance of neurons and has been implicated in various neurodegenerative diseases.