However, cancer cells maintain high amounts of NAD+ mainly by upregulation of the NAMPT enzyme.8,64,215 It is also known that the normal stem cells have large pools of NAD+, similar to cancer cells,188 and the upregulation of NAMPT in these tumor cells with concomitant raise of NAD+ levels de-differentiate these cancer cells to CSC like cells.8,64,215 It is possible that, with aging, the decrease in NAD+ not only affect the mature tissue but also stem cells, losing regenerative capability. This evidence concerns the gene NAMPT and neoplasm.