RET and brain neoplasm: Importantly, the effect of CPT in aging, age-related AD pathogenesis, and brain tumor settings can be faithfully recapitulated by the supplementation of the NAD+ precursors of nicotinamide mononucleotide (NMN) and nicotinamide riboside (NR), supporting the notion that the NAD+/NADH ratio is a key mediator of the biological effects of RET inhibition by CPT.