Research has found that mitochondrial oxidative capacity and NAD biosynthesis are reduced in human sarcopenia across ethnicities (Migliavacca et al., 2019), and reducing NAD levels by ablating nicotinamide phosphoribosyltransferase (NAMPT)-mediated NAD salvage could lead to progressive muscle degeneration in the adult mouse (Frederick et al., 2016). The gene discussed is NAMPT; the disease is sarcopenia.