We assessed the relevance of this observation in vivo by analyzing seventeen [18F]PI-2620 tau PET scans of patients with PSP-RS and a high likelihood of underlying 4R-tauopathy and nine healthy controls with an MRI-based layer segmentation of gray matter and WM/GM boundary areas of the frontal cortex (Supplemental Fig. 10). This evidence concerns the gene MAPT and supranuclear palsy, progressive, 1.