ORMDL3 and allergic rhinitis: In this study we provide potentially novel evidence that ORMDL3 expression selectively in ASM can induce increased ASM hypertrophy, proliferation, and contractility, which together may help explain the epidemiologic linkage of chromosome 17q12-21 to the development of childhood onset asthma (1) (where ASM can express ORMDL3 in the lower airway) but not to the development of allergic rhinitis (7) (where there are no ASM cells in the nasal mucosa).