Moreover, recent data have demonstrated that pharmacological inhibition of NAMPT by FK866 can be counterbalanced by rescue of NAD+ production from precursors other than NAM, notably NMN and Nicotinamide riboside (NR).82 Specifically, different FK866-treated tumor cells are affected by two ectoenzymes that are able to produce NAD+ precursors. This evidence concerns the gene NAMPT and neoplasm.