TARDBP and supranuclear palsy, progressive, 1: Our results demonstrate that [18F]-Flortaucipir, [18F]-MK-6240 and [18F]-PI-2620 have a similar high binding affinity for tau aggregates in AD brain tissue, but none of them seems to bind to a significant extent to tau aggregates in non-AD tauopathies such as PiD, PSP, CBD or CTE, or to Aβ, α-synuclein or TDP-43-containing lesions.