Since tau has been proposed as a mediator of Aβ-pathology in synaptic and memory function in AD [18], AAV9-hTauP301L was injected bilaterally in the dorsal hippocampi of 3-month-old APP/PS1 mice to analyze the interactions between tau and Aβ in the pathogenesis of AD. The gene discussed is MAPT; the disease is Alzheimer disease.