STAT3 and immunodeficiency disease: PIDDs to consider in this context include hyper-IgE syndrome (STAT3 or DOCK8 deficiency) [15], immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome (IPEX syndrome), Omenn syndrome [14, 17], Wiskott-Aldrich syndrome [14, 15], and other rare combined immunodeficiencies.