The hNEX t-tau level was significantly higher in the Mild-AD group than the AMC and MCI groups (AMC, 16.16 ± 2.81; MCI, 17.45 ± 2.84; Mild-AD, 34.28 ± 7.58, both p < 0.05, Figure 2B). Here, MAPT is linked to Alzheimer disease.