MAPT and Alzheimer disease: The authors suggested that AV‐1451 binds stronger to the paired helical filaments of tau seen in AD compared to the predominantly straight tau filaments typical of PSP.19, 20, 24 The discrepancy between AV‐1451 PET retention in the basal ganglia and the autoradiography could be a result of lower affinity of the radiotracer to tau aggregates in vitro than in vivo, in addition to an already low binding to straight tau filaments.