t-tau and p-tau were strongly correlated with SNAP-25 in CN (r = 0.483, p < 0.001 for t-tau; r = 0.522, p < 0.001 for p-tau), sMCI (r = 0.876, p < 0.001 for t-tau; r = 0.858, p < 0.001 for p-tau), pMCI (r = 0.642, p < 0.001 for t-tau; r = 0.528, p < 0.001 for p-tau), and AD subjects (r = 0.791, p < 0.001 for t-tau; r = 0.644, p = 0.004 for p-tau) (Fig. 4a, c). Here, MAPT is linked to Alzheimer disease.