AIRE and autoimmune polyendocrine syndrome type 1: Studies of a rare monogenic disorder – autoimmune polyendocrine syndrome type 1 (APS1) or autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) and the mutated gene underlying the disease, Autoimmune regulator (AIRE) – have shed light on how reaction against self is avoided.