NPTX2, which expresses on GABAergic neurons inhibiting excitatory pyramidal neurons (Chang et al., 2010), was downregulated in the frontopolar cortex of AD patients (Xiao et al., 2017), which causes the excitatory/inhibitory imbalance of memory impairment (Xiao et al., 2017). This evidence concerns the gene NPTX2 and Alzheimer disease.