IFNG and aspergillosis: To conclude, though loss-of-function mutations in STAT3 gene is a rare primary immunodeficiency, and our study is limited by the number of STAT3-deficient patients, our data indicates that STAT3-deficient patients, particularly those with aspergillosis, exhibit adaptive immune defect by producing lower IFN-γ and Th17 responses toward A. fumigatus infection but not any defects in their innate immune functions.