INS and Alzheimer disease: Insulin plays neurotrophic, neuromodulatory,and neuroendocrineroles in the brain.11,18 The insulin signaling pathwayregulates neuronal apoptosis, β- and γ-secretases activity,amyloid precursor protein (APP), and Tau phosphorylation.19−21 Alterations in its pathway can lead to Aβ buildup, NFT formation,oxidative stress, neuroinflammation (activation of astrocytes andmicroglia), changes in glucose metabolism and apoptosis, elementspresent in AD.11−13,16,18