Kim and colleagues reported that deficits in regulatory B cells, defined as CD19+CD24hiCD38hi or CD19+PD-L1hi, are reversed up to 1 year following alemtuzumab treatment [22], and Grutzke and colleagues [10] have reported that CD19+CD27-CD38hi B cells from MS patients secrete high levels of IL-10. This evidence concerns the gene CD19 and myeloid sarcoma.