TARDBP and Alzheimer disease: 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.