MAPT and supranuclear palsy, progressive, 1: While the first-generation tau PET tracer 18F-Flortaucipir failed to track the neuropathological staging of PSP-related changes [6], possibly because of off-target binding [4], the positive correlation between 18F-Florzolotau pathological staging system and clinical severity as per PSPrs score suggest that 18F-Florzolotau may serve as a promising biomarker of 4R tau pathology in PSP.