For example, flortaucipir (18F-AV1451, 18F-T807) shows potent and specific non-displaceable binding to tau neurofibrillary tangles in postmortem AD brain tissue.s73–75 Flortaucipir is selective for tau, and does not significantly bind to beta amyloid, alpha-synuclein or TDP-43.s73 The pattern of binding relates to clinical phenotype, cognitive profile, and Braak and Braak staging of AD.s76 s77 However, in other non-Alzheimer’s tauopathies, the utility of this ligand is less clear.s75 Some studies have used tau PET to investigate patients with repetitive TBI produced by sports injuries. Here, MAPT is linked to Alzheimer disease.