Dr. Prof Stephan Ehl is the Director of the Immunodefficiency department at the University of Freiburg, Germany (RITA member since 2017). Stephan Ehl’s group has been collaborating with Frederic Rieux-Laucat (Immunogenetics of Pediatric Autoimmune Diseases – Imagine Institut, Necker Children’s Hospital) to identify SOCS1 haploinsufficiency as a cause of a complex autoimmune-lymphoproliferative disorder. Dr. Jerome Hadjdaj (Immunogenetic Imagine Institut, Necker Children’s Hospital) and Stephan Ehl have initiated a level 3 ESID registry study on this disease: https://www.uniklinik-freiburg.de/cci/studien/socs1-registry.html They have now collected around 40 Patients with detailed information and would like to publish an overview over this cohort within this year. For this, they would like to better characterize the spectrum of disease manifestations and response to therapy in patients with SOCS1 haploinsufficiency. They are therefore calling for other HCP members treating patients with SOCS1 haploinsufficiency that are interested in contributing to this study, to contact them or the study coordinator via this website: https://esid.org/Working-Parties/Registry-Working-Party/Studies/SOCS1-Study