• Upregulated in human AD and animal models of AD (Zhou et al., 2021).• Increased TSPO PET levels occur in a region-dependent manner in AD (Tournier et al., 2020).• Increased TSPO PET levels are positively correlated with aggregated Aβ and tau in MCI and AD patients (Parbo et al., 2017; Dani et al., 2018; Chandra et al., 2019). Here, TSPO is linked to Alzheimer disease.