Tracer kinetics and binding characteristics of [18F]PI-2620 in clusters of subcortical areas were not different between clinically diagnosed 3/4R and 4R tauopathies, Since inverted U-shape time-SUVR curves of [18F]PI-2620 were also observed in healthy controls,32 we speculate that the effect of binding affinity to tau deposition is dominated by the general tracer kinetics in subcortical regions. This evidence concerns the gene MAPT and tauopathy.