GSK3B and Alzheimer disease: On the other hand, Parkin, the product of the PARK2 gene, has been reported to inhibit Wnt signaling [91], whereas α-Synuclein, a presynaptic protein causal in PD, contributes to GSK-3β-catalyzed Tau (a protein linked to tauopathies, such as AD) phosphorylation (pTau) in PD disease models [66].