The pathophysiology of asthma has been attributed to an inflammatory process that occurs predominantly in the large airways through the accumulation of eosinophils and CD4+ T lymphocytes in the submucosa, mucous-gland hyperplasia, thickening of the subepithelial collagen layer, submucosal matrix deposition, mast cell degranulation, and hypertrophy and hyperplasia of the airway smooth muscle (2). The gene discussed is CD4; the disease is asthma.