Pro-inflammatory T helper (Th) 17 cells are required for the pathogenesis of MS (3, 4) and its mouse model, the experimental autoimmune encephalomyelitis (EAE), whereas CD4+Foxp3+ regulatory T cells (Treg), crucial for preventing autoimmunity, are defective in numbers and functions (5). The gene discussed is FOXP3; the disease is Autoimmunity.