In our study, we showed that the expression of CST7 in the brains of APP/PS1 mice was evidently increased compared with WT mice, while that was notably decreased after TSA treatment, suggesting that the alleviation of anxiety- and depression-like behaviors in APP/PS1 may also benefit from TSA due to its inhibition of CST7 expression in their brains. This evidence concerns the gene APP and major depressive disorder.