Low levels of IL-17, as well as a myriad of immune function losses associated with a STAT3 deficiency, manifest as “cold” soft tissue abscesses, recurrent pneumonias, chronic eczema, connective tissue abnormalities, skeletal defects, and an increased susceptibility to skin and lung infections, the classic symptoms of AD-HIES. Here, STAT3 is linked to susceptibility to pneumonia measurement.