In the past, the TSPO radiotracer ligand [11C]PK11195 was successfully applied to depict glial activation in various CNS diseases like multiple sclerosis, Huntington’s disease, amyotrophic lateral sclerosis, Alzheimer’s disease, traumatic brain injury, and ischemic stroke (32–35). The gene discussed is TSPO; the disease is early-onset autosomal dominant Alzheimer disease.