IGHE and polyendocrinopathy: A mutation in the Foxp3 gene was found to lead to immune dysregulation, polyendocrinopathy, enteropathy, and X-linked (IPEX) syndrome in humans, and to various autoimmune, inflammatory, and allergic conditions in scurfy mice, with lymphocyte infiltration into multiple organs, and the development of hyper-IgE-emia [27, 28].