IDO1 and Alzheimer disease: In AD, IDO regulates the release of neurotoxic pro-inflammatory cytokines (IL-1β, IL-6, TNF-α) in the brain and influences the proteins (mTOR, GCN2 (general control nonderepressible 2; a serine/threonine-protein kinase that senses amino acid deficiency through binding to uncharged transfer RNA) and eIF2-α (eukaryotic translation initiation factor 2) implicated in AD’s pathogenesis [61].