It mediates essential functions in asthma, including induction of the IgE isotype switch, expression of vascular cell adhesion molecule-1 (VCAM-1), and promotion of eosinophil transmigration across the endothelium, mucus secretion, and differentiation of T helper type-2 lymphocytes leading to cytokine release which causes asthma symptoms (Steinke and Borish, 2001). This evidence concerns the gene IGHE and asthma.