CDK5 and Alzheimer disease: Overall, our data from this early-phase AD mouse model suggest that ibrutinib ameliorates tau hyperphosphorylation by downregulating tau kinase CDK5 phosphorylation, PD180970 enhances tau hyperphosphorylation by upregulating the tau kinase DYRK1A, and cabozantinib partially attenuates tauopathy by suppressing CDK5 phosphorylation.