Heterogeneous disorders of the immune system have variably been described in HIES patients, including impaired production of interferon gamma by T cells, defective T helper 1 (Th1)-dependent cytokine response, a skewed Th1/Th2 cell ratio, a diminished memory T-cell populations, decreased delayed-type hypersensitivity responses, an impaired response of lymph cells to antigenic and alloantigenic stimulation [86], as well as a defective neutrophil chemotaxis [3]. The gene discussed is IFNG; the disease is hyper-IgE syndrome.