Our findings of higher initial uptake and much faster clearance in the putamen and the globus pallidus in comparison to cortical regions are similar to reports on kinetic characteristics of [18F]AV-1451.49, –51 Keeping in mind that our [18F]PI-2620 study analyzed assumed tau-positive clusters and earlier [18F]AV-1451 studies used predefined brain regions, the increasing time-SUVR curves for AD subjects and the inverted U-shape of time-SUVR curves for 4R tauopathy subjects of our study correspond well with the aforementioned studies. The gene discussed is MAPT; the disease is tauopathy.