TSPO and Alzheimer disease: Regional tau again appeared as the strongest driver of TSPO-PET signals in AD-CBS (β = 0.357, p < 0.001) and typical AD (β = 0.412, p < 0.001) with high proportions of regional TSPO-PET positivity in regions with significant tau accumulation (AD-CBS: 81%, typical AD: 79%; Fig. 3B/C).