MARK2 and Alzheimer disease: In the case of GSK3β factor, for instance, it is a ubiquitously expressed serine/threonine kinase interacting with extrasynaptic NMDARs in PI3K-Akt signaling, which contributes to tau phosphorylation, Aβ generation, and neuronal death, hence implying the involvement of trophic receptors in AD pathogenesis through the PI3K-Akt signaling pathway [62, 63].