GSK3B and Alzheimer disease: In particular, GSK3β activation, due to reduced pGSK3βSer9 [28], but also through increased phosphorylation of GSK3β at Y216 [29], has been strongly implicated in the phosphorylation of Tau microtubule-associated protein at the majority of its serine/threonine sites that cause associated toxicities in Alzheimer’s disease (AD).