CD38 deficiency has improved glucose intolerance with HFD, which could be further ameliorated by supplement of NR.52 78c, as a highly specific and effective CD38 inhibitor, can reverse age-associated NAD+ reduction and improve some metabolic and physiological parameters of aging, such as glucose tolerance, cardiac function, muscle function and exercise capacity in both natural aging and accelerated aging mice models.53 The gene discussed is CD38; the disease is hyperinsulinemic hypoglycemia, familial, 4.