FOXP3 and immune dysregulation-polyendocrinopathy-enteropathy-X-linked syndrome: In scurfy mice, loss-of-function mutations in Foxp3 result in the development of a fatal autoimmune disorder6 while in humans FOXP3 mutations lead to an X-linked disorder, IPEX (immunodysregulation polyendocrinopathy enteropathy X-linked)7–9.