Autoimmune polyendocrine syndrome type I (APS-1) is a rare hereditary disorder of the immune system that affects both endocrine and non-endocrine tissues. The cause of this disorder is mutations in the autoimmune regulator (AIRE) gene. This gene encodes a putative transcription factor in medullary thymic epithelial cells. Due to the fact that APS-1 possesses similar features with common autoimmune disorders such as type 1 diabetes, Hashimoto's thyroiditis, autoimmune premature ovarian failure and Addison's disease, it has proven to be an invaluable model system in understanding autoimmune reactions. The EU-funded project ‘Autoimmune polyendocrine syndrome type I - a rare disorder of childhood as a model for autoimmunity’ (Euraps) joined top scientists in the field of autoimmune diseases from three continents, Asia, Australia and Europe. In particular, the consortium collectively worked on the rare hereditary disorder APS-1 as a model system of autoimmune diseases. Effective and successful collaboration of the Euraps partners led to tackling many current obstacles in the field. Moreover, a much higher awareness among European clinicians for early diagnosis and prognosis was built, and new therapeutic strategies were planned. The knowledge produced over the three years of Euraps was disseminated to the community by the publication of scientific articles in a number of top ranking journals. The Euraps network achieved all of its objectives promoting APS-1 as an important and efficient model for the deeper study of autoimmunity. Understanding the mechanism of the development of autoimmunity in humans will facilitate the discovery of new drug targets and subsequently the creation of novel therapeutic approaches.