TSPO and myeloid sarcoma: First andsecond-generation PET radioligands are able to bind to the translocatorprotein (TSPO) expressed by microglia/macrophages, 18 kDa TSPO and lesser toastrocytes in diverse neurological conditions.53 In MS, histopathological studies have shown that TSPO uptake is amarker for chronic active lesions and have demonstrated an association withrim-positivity on susceptibility MRI.54