NMNAT1 and blindness (disorder): Importantly, while a crucial role for retinal NAD+ was recently described through characterization of mice conditionally lacking the NAD+ pathway enzyme NAMPT in photoreceptors (Lin et al., 2016), the significance of nuclear-synthesized NAD+ in vision—suggested by the fact that NMNAT1 is the only NAD+-pathway enzyme to date linked to blindness—remains poorly understood.