Steroids, leukotriene antagonists, short- and long-acting bronchodilators, anticholinergic agents, anti-IL4 and IL-5 treatments, anti-IgE antibody and combination therapies (including inhaled corticosteroid, long-acting bronchodilator, and anti-muscarinic agent) are all common asthma treatments, but the symptoms of asthma are not adequately controlled with currently available therapy. Here, IL4 is linked to asthma.