VIP and Alzheimer disease: Reasoning that the derivative of vinpocetine may elicit these pharmacologic functions, we undertook a validation study and discovered that p-GSK3β (Tyr216) led to an increase in stimulation of GSK3β in the AD group compared with that in the WT group, and VIP@siBACE1 and VIP@siScr treatment significantly decreased Tyr216 phosphorylation in the hippocampus and cortex of APP/PS1 mice compared with that in the AD group (Fig. 5c and Supplementary Fig. S13c).