CD8 T cells accumulating in brain tissue of MS patients are mainly effector memory T cells (CD45RA-, CD45RO+, CCR7-) that express the activation marker CD69, the costimulatory molecule CD137 and the apoptosis inducing TNF family member CD95L, and produce IFNγ (62, 114, 117). Here, CD8A is linked to myeloid sarcoma.