Recent studies have clearly defined the differential roles of IL-4 and IL-13 in allergic inflammation; IL-4 preferentially regulates Th2 cell function and IgE synthesis, whereas IL-13 mediates the pathophysiological processes that control mucus production, eosinophilia and AHR (Gour and Wills-Karp, 2015). The gene discussed is IL13; the disease is Increased total eosinophil count.