Through the analysis of the differentially expressed genes (DEGs) of two GEO datasets including controls of AD and scientific publications, potential molecular and cellular mechanisms associated with the DEGs, which are involved in Aβ and tau pathologies, impaired autophagy, synaptic dysfunction, neuronal cell death, neurodegeneration, cognitive decline, and repressed adult neurogenesis, are identified in the entorhinal cortex (EC) and/or hippocampus (HC) of females and males with AD. The gene discussed is MAPT; the disease is Alzheimer disease.