The cells recently found to be affected in MS include GM-CSF-secreting effector T cells (9), DR2a and DR2b-derived self-peptides specific CD4+ T cell clones (10), glutamate producing Th17 cells (11), GM-CSF+ CXCR4+T cells (12), CD4+CD25hiCD127lowFOXP3+ Tregs (13), MBP-specific CD8+ T cells (14), circulating CD8+ CD20+ T memory cells (specific to myelin) (15) and regulatory B cells (Bregs) producing IL-10 and IL-35 (16). The gene discussed is CXCR4; the disease is myeloid sarcoma.