In this article, AD-like pathologies represented by mitochondrial dysfunction, Aβ overproduction, synaptic loss, and memory deficits were observed in 9-month-old APP/PS1 transgenic mice (abbreviated as the APP/PS1 group) in comparison to age-matched wild-type C57/BL6 mice (abbreviated as the wild-type group). The gene discussed is PSEN1; the disease is Alzheimer disease.