In view of increase in vulnerability of neurons to degeneration upon NAD deficiency [57] and prevention of degeneration of transected axons following exogenous application of NAD or nicotinamide [58], the neuroaxonal degeneration observed in multiple sclerosis with PP-MS and SP-MS may be partly related to reduction of visfatin/NAMPT as a rate-limiting enzyme generating NAD. This evidence concerns the gene NAMPT and multiple sclerosis.