Evidence for the exhaustion of EBV-specific CD8+ T cells in MS comes from a study by Pender et al. [20], who found that MS patients, compared to healthy controls, have decreased CD8+ T cell response (indicated by the production of IFN-γ, TNF-α, and IL-2) to EBV lytic, but not CMV lytic, antigens. This evidence concerns the gene TNF and myeloid sarcoma.