CDK5 and Alzheimer disease: We previously showed increased levels of pro-inflammatory cytokine interleukin-18 (IL-18) in different regions of AD brains, where it co-localized with Aβ-plaques, as well as the ability of IL-18 to increase expression of glycogen synthase kinase-3β (GSK-3β) and cyclin dependent kinase 5, involved in hyperphosphorylation of tau-protein.