BACE1 and Alzheimer disease: Compared with that in the WT group, the concentration of BACE1 in the hippocampus and frontal cortex in the AD group, ADS group and ADT group was higher (P < 0.001); however, compared with that in the AD group and ADS group, the concentration of BACE1 in the hippocampus and frontal cortex in the ADT group was significantly decreased (P < 0.001).