CNTF and retinal degeneration: Neuroprotective factors that support the survival of retinal cells, such as glial cell-derived neurotrophic factor (GDNF), ciliary neurotrophic factor (CNTF), brain-derived neurotrophic factor (BDNF), basic fibroblast growth factor, and pigment epithelium-derived factor (PEDF) have shown promise in mouse models of retinal degeneration.67