TSPO and Alzheimer disease: Since TSPO expression can also be expressed by astrocytes (Lavisse et al., 2012; Notter et al., 2020), and astrocytic TSPO levels increase before microglial TSPO in Alzheimer’s disease (Tournier et al., 2020), it is plausible that astrocytes are the primary source of cortical TSPO in people with schizophrenia and elevated inflammation.