Also, in the mouse experimental NEC model, NR administration alleviated OXS, increased NAD+ levels and intestinal microcirculatory perfusion, and relieved signs of endothelial dysfunction by modulating the SIRT1-associated endothelial nitric oxide synthase (eNOS) acetylation/deacetylation pathway [39,42]. The gene discussed is NOS3; the disease is endothelial dysfunction.