Furthermore, the finding of decreasing microglial TSPO expression over time and higher astrocytic TSPO expression in lesions with signs of chronicity, i.e., astrogliosis, again is consistent with studies demonstrating decreases in the percentage of TSPO contributed by microglia/macrophages and increases in the percentage contributed by astrocytes in chronic active and inactive MS lesions [21]. Here, TSPO is linked to myeloid sarcoma.