Furthermore, although it has been reported that alemtuzumab induces a relative sparing of Fox3P positive, T regulatory cells as shown here, which favours the regulation of CD4 T cells,41, 42 in MS there is a substantial reduction in the absolute number of regulatory T cells and CD8+ T cells.11, 41 Hence, following alemtuzumab treatment, B cells repopulate in the relative absence of CD4 T regulatory cells and CD8 T suppressor cells. The gene discussed is CD8A; the disease is myeloid sarcoma.