Compared to controls, AD patients had significantly higher NDEV levels of Aβ42 (p < 0.05; average CD81-adjusted levels: 19.60 pg/ml versus 5.00 pg/ml), total-tau (p < 0.01; CD81-adjusted levels: 110.58 pg/ml versus 38.71 pg/ml), P-T181-tau (p < 0.001; CD81-adjusted levels: 48.79 pg/ml versus 15.10 pg/ml), and P-S396-tau (p < 0.05; CD81-adjusted levels: 32.63 pg/ml versus 17.78 pg/ml), and significantly lower NDEV concentrations of NRGN (p < 0.01; CD81-adjusted levels: 288.02 pg/ml versus 498.61 pg/ml) (Table 1). Here, CD81 is linked to Alzheimer disease.