MAPT and Alzheimer disease: Extensive studies using pre-clinical models of AD have demonstrated that increasing nicotinamide adenine dinucleotide (NAD+) levels through supplementation with NAD+ precursors (e.g., nicotinamide and its derivatives nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN)) stimulates mitophagy; mitigates Aβ, tau, and impaired energy metabolism; and modulates the inflammatory response, improving cognitive function [263,264,265,266].