Asthma was long thought to be an allergic disease that is mediated by excessive T-helper (TH)2-cell production of interleukin (IL)-4, IL-5, IL-9, and IL-13, which drive immunoglobulin E production, eosinophilia, mast-cell activation, and mucus secretion by airway epithelial cells (2). The gene discussed is IL5; the disease is Increased total eosinophil count.