These findings clearly define the age‐gradient changes in the autophagy–lysosome system, the endosome/lysosome system, and the SGK1/FOXO3a pathway in the hippocampus of APP/PS1 mice, providing new perspectives and clues for understanding the possible mechanisms of AD, especially the transition from compensatory to decompensated state. This evidence concerns the gene SGK1 and Alzheimer disease.