In addition to its widespread usage in common autoimmune conditions, CTLA4-Ig has already been successfully used to control inflammation in primary immunodeficiencies such as CTLA4 or LRBA deficiency [3, 23, 24], with our results here suggesting it may additionally serve to control IPEX disease. Here, CTLA4 is linked to immune dysregulation-polyendocrinopathy-enteropathy-X-linked syndrome.