STAT3 and hyper-IgE syndrome: The mutations of Signal Transducer and Activator of Transcription 3 (STAT3) in peripheral T cells of autosomal dominant (AD) form of HIES (AD-HIES) patients reduced the expression of RORγt which is essential for Th17 differentiation (Al Khatib et al., 2009; McDonald, 2012).