NAMPT and metabolic dysfunction-associated steatotic liver disease: Indeed, Choi et al. also reported that the elevation of hepatic miR-34a is related to the severity of NAFLD and reduced SIRT1 in the liver on account of targeting nicotinamide phosphoribosyltransferase (NAMPT) and, consequently, impairing NAD biosynthesis (Choi et al., 2013).