CD4 and myeloid sarcoma: In our study, not only have we observed that approximately 50% of naive CD4+ T cells in cord blood produce IL-8 upon activation, we also demonstrated a similar proportion of IL-8–producing naive T cells in the blood of MS patients, with newly generated naive T cells appearing following T and B cell depletion with alemtuzumab (Figure 3 and Supplemental Figure 3).