A local, deleterious “cytokine storm” and ongoing cytotoxic activity are both compatible with the concept that CD8+ T cells recruited to the MS brain might be activated by a persistent EBV infection in the CNS, more specifically by EBV-infected B cells accumulating in the CNS connectival spaces (Serafini et al., 2007, 2019; Veroni et al., 2018). This evidence concerns the gene CD8A and myeloid sarcoma.