Fabio Candotti is a pediatric immunologist who acquired his clinical training in PIDs and HSCT at the University of Brescia, Italy before moving to the NIH in the USA. At the NIH, he led a clinical and research group focused on the investigation of the genetic and cellular bases of PIDs and the development of gene therapy for these diseases. He conducted several clinical trials of gene therapiy for ADA-deficient SCID, before retruning to Europe in 2014 to join the University Hospital of Lausanne where he continues his clinical and research activities in the field of PIDs.