NMNAT1 and familial dilated cardiomyopathy: Notably, the expression of genes encoding proteins regulating the production of NAD+ from NAM, such as Nampt and Nmnat1, which encodes nicotinamide nucleotide adenylyltransferase 1, was decreased at all stages of DCM, and Nampt protein declined at 6 months of age (Fig. 3d,e and Extended Data Fig. 6).