CD8+ T cells are present in the perivascular cuffs in MS lesions and in the NAWM, are clonally-expanded, and exhibit a tissue-resident, effector memory phenotype characterized by high expression of activation (CD69, Ki67, ICOS) and cytotoxic (FasL, granzyme B) markers and pro-inflammatory cytokines (IFN-γ, tumor necrosis factor (TNF)) (51, 102). This evidence concerns the gene CD8A and myeloid sarcoma.