TNFRSF9 and myeloid sarcoma: DP T cells in HTLV-1 carriers also expressed high levels of activation induced markers CD154, CD137, and CD69 in response to HTLV-1 stimulation, and CD49d+CD154+ lymphocytes have been shown to reprogram oligodendrocytes into immune reactive cells in MS (59), further supporting the potential for DP cells in HTLV-1 infection to contribute to CNS pathology.