NSC transplantation restores spatial learning ability in 18-month-old 3xTg-AD mice by elevating hippocampal BDNF level (Blurton-Jones et al., 2009), and stimulating NSC proliferation in 7-month-old 3xTg-AD mice by activating the PI3K-AKT-GSK3β-Wnt pathway results in increased cognitive function (Zheng R. et al., 2017). This evidence concerns the gene BDNF and Alzheimer disease.