The treatment of neurons derived from these AD patients with β-secretase inhibitors significantly reduced the levels of hyperphosphorylated tau and aGSK-3β, whereas a γ-secretase inhibitor showed no effects compared to controls, suggesting direct crosstalk between APP proteolytic processing during the activation of GSK-3β and tau phosphorylation in human neurons (Israel et al., 2012). Here, MAPT is linked to Alzheimer disease.