MAPT and Alzheimer disease: Significantly higher levels of plasma T-Tau were found in the AD family (34.51 ± 9.91 pg/ml; p < 0.0001), PD family (26.64 ± 10.36 pg/ml; p < 0.0001) and FTD (41.53 ± 20.51 pg/ml; p < 0.0001) than in the NC group (17.46 ± 9.28).