TSPO and schizophrenia: Until now, the only method to investigate microglia cells in the brain in vivo is positron emission tomography (PET) using TSPO ligands.10 In classic central nervous system (CNS) autoimmune disorders such as multiple sclerosis increased binding of TSPO ligands was demonstrated.11 However, full-blown neuroinflammation is less evident in schizophrenia.12 PET studies examining TSPO binding in patients with schizophrenia have provided inconclusive results.