Given the PET evidence of increased TSPO radioligand binding in core pathological regions, and its predictive value for clinical decline, we suggest that TSPO PET can be used to quantify microglial-mediated neuroinflammation in primary tauopathies such as PSP, assisting the design of clinical trials with disease-modifying therapies. Here, TSPO is linked to supranuclear palsy, progressive, 1.