APP and Alzheimer disease: To further clarify the effect of TLR2 on neurobehavioral and pathological changes in AD, in the present study, we used APPswe/PSEN1dE9 transgenic (AD, App+Psen1+) mice and TLR2 gene knockout (TLR2KO, Tlr2-/-) mice to generate Tlr2-/-App+Psen1+ (AD-TLR2KO) mice.