sEV 3R/4R tau ratios in plasma-derived sEV in genetic cases from Sant Pau cohort (n = 34 genetic cases) stratified by clinical diagnosis, HC versus bvFTD P = 0.000009, HC versus PSP P = 0.000007, ALS versus bvFTD P = 0.0000091, ALS versus PSP P = 0.0000016, ALSFTD versus bvFTD P = 0.0000074, ALSFTD versus PSP P = 0.0000041, bvFTD versus PSP P = 0.000006; **** P < 0.00001;