FOXP3 and immune dysregulation-polyendocrinopathy-enteropathy-X-linked syndrome: For instance, disruption of Tregs due to deleterious variants in the FOXP3 gene result in immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome (IPEX syndrome), which is characterized by multiorgan autoimmunity due to loss of peripheral tolerance from absent or dysfunctional Tregs (4–9).