In a key validation step, we translated the in vivo tau-PET analyses to two independent postmortem samples (Munich-European consortium/collection): n = 97, University of Pennsylvania [UPENN]: n = 96) with confirmed PSP pathology and gold-standard regional histopathological 4 R tau assessments and further performed in vitro binding assays and autoradiographic analyses that support PI-2620 binding to 4 R tau. Here, MAPT is linked to supranuclear palsy, progressive, 1.