ANPEP and Alzheimer disease: In this study, we found that the expression level of the BMAL1 protein in the hippocampus of APN‐KO mice increased significantly at CT4, CT12, CT16 and CT20, However, Studies have shown that BMAL1 protein was attenuated in 5XFAD cortex,48 whilst the protein levels of BMAL1 are significantly elevated in impaired astrocytes of cerebral cortex from patients with AD.49