The category of immune dysregulatory syndromes contained both anticipated findings: FOXP3 (IPEX syndrome) and FAS (autoimmune lympoproliferative syndrome)–both known to be associated with eosinophilia/elevated IgE–and surprises: identifying conditions in which allergic inflammation is less prominent (CTLA4 and LRBA) or to our knowledge, unreported, as a clinical feature (MAGT1) (33–36). This evidence concerns the gene FAS and immune dysregulation-polyendocrinopathy-enteropathy-X-linked syndrome.