Moreover, as an enzyme, intracellular NAMPT or iNAMPT is responsible for regeneration of intracellular NAD+, which is a multifunctional co-factor in many cellular events, such as transcriptional regulation, longevity and caloric-restriction responses, cell cycle progression, apoptosis, DNA repair, circadian rhythms, chromatin dynamics regulation, and telomerase activity, processes closely related to cancer pathogenesis6. Here, NAMPT is linked to cancer.