Foxp3 deficient mice (‘scurfy') and patients with defective or absent FOXP3 expression (IPEX, immune dysregulation, polyendocrinopathy, enteropathy, X-linked, syndrome) have high levels of circulating autoantibodies suggesting that the Treg cells defect is also followed by B cell dysfunction22, 23. The gene discussed is FOXP3; the disease is polyendocrinopathy.