TSPO and glioma: Although it is not yet clarified to which extent inflammatory cells such as tumor-associated microglia/macrophages contribute to the signal of TSPO PET in gliomas, TSPO PET has been suggested to be an interesting tool for glioma characterization, as a positive correlation of TSPO expression with histological tumor grade [15,16] and a negative association with patient’s survival have been reported [17].