To clarify the onset time of NPSs and cognitive impairment in the course of AD, we first assessed emotional and cognitive behaviors by using an AD mouse model and found that the young APP/PS1 mice showed abnormal behaviors, including longer total distance, increased center exploration in the open‐field test (OFT), and more time in the open arms in the elevated plus maze (EPM) paradigms at postnatal weeks 8 (PW8) and PW12, while the 24‐week‐old APP/PS1 mice showed memory impairment in the fear conditioning test (FCT) (Figure 1a–d). The gene discussed is APP; the disease is memory impairment.