GSK3B and neurodegenerative disease: GSK3β is associated with various neurodegenerative diseases including AD and PD.33 GSK3β activation is involved in both neurotoxin-induced and genetic factor-induced DA neuronal loss.34 Accordingly, the active form of GSK3β (p-GSK3β Tyr216) is increased in the striatum of postmortem samples of PD.35 In addition, MPTP animals show the hyperphosphorylation of Tyr216 and dephosphorylation of Ser9 in GSK3β.