NOS2 and glaucoma: For example, neurotrophins, such as brain-derived neurotrophic factor and ciliary neurotrophic factor, protect retinal ganglion cells (RGCs) and promote axon regeneration in an ONI model.4, 5, 6 In addition, inhibition of neuroinflammatory events such as upregulation of tumor necrosis factor (TNF)-α and nitric oxide synthase (NOS) may be effective for RGC protection following ONI.7 The ONI model mimics some aspects of glaucoma, including RGC death induced by excitotoxicity and oxidative stress, and therefore it is also a useful animal model for glaucoma.