STAT3 and immunodeficiency disease: Hyper-immunoglobulin E syndrome (HIES) is a rare immunodeficiency disorder with two classifications: autosomal-dominant hyper-IgE syndrome (AD-HIES) caused by a signal transducer and activator of transcription 3 (STAT3) gene mutation, and autosomal-recessive hyper-IgE syndrome (AR-HIES) caused by mutations in either dedicator of cytokinesis 8 (DOCK8), PGM3, TKY2, and SPINK5 genes [1,2]. Although the incidence of HIES is less than 1/100,000, it is more prevalent in regions with consanguineous populations [3,4].