MAPT and Alzheimer disease: As reported previously,24,25 disease-specific tau-CTFs, 21, 34 and 39 kDa tau in PiD, 22 and 33 kDa tau in PSP, 22, 37–40 and 43 kDa tau in CBD and 19, 22, 25, 30, 36 and 40 kDa tau in Alzheimer’s disease were also detected (Fig. 1A and Supplementary Fig. 1).