The use of specific radiopharmaceuticals targeting TSPO in combination with positron emission tomography (PET) imaging has allowed activated glia to be observed in patients with Parkinson's disease (Ouchi et al., 2005), multiple sclerosis, glioma (Tarkkonen, Rissanen, Tuokkola, & Airas, 2016), amyloid lateral sclerosis (Turner et al., 2004), and Huntington's disease (Rupprecht et al., 2010). Here, TSPO is linked to glioma.