Interestingly, in age‐matched WT mice, Mt3 expression increased from 1 to 6 months of age, which is consistent with previous findings that Mt3 levels rise with normal aging in both rodents and humans (Figure 1b).[25, 26] This age‐associated upregulation has been proposed to reflect a compensatory response to oxidative stress in the aging brain.[27] Therefore, the Mt3 downregulation observed in AD mice likely reflects a disease‐specific pathological regulation, rather than a general age‐related or developmental change. This evidence concerns the gene MT3 and Alzheimer disease.