TSPO and astrocytoma (excluding glioblastoma): For example, [11C]-PK 11195 reliably monitors increases in TSPO expression in brain tumors (including malignant astrocytomas), as well as in the activated microglia found in patients with multiple sclerosis, stroke, epilepsy, Alzheimer's disease, Huntington's disease and AIDS [2], [3], [4], [5], [6], [7], [8], [9], [10].