Another conviction is that because patients with ABPA have an exaggerated response to IL-4 and produce a large amount of IgE, IgG, and IgA antibodies against A. fumigatus antigens, a gain of function polymorphism in the IL-4 receptor-α chain may be responsible for this situation (17). The gene discussed is IGHE; the disease is allergic bronchopulmonary aspergillosis.