IL13 and asthma: In the subgroup analysis by atopic status, the IL-13 −1112C/T polymorphism was significantly associated with risk of atopic asthma (OR = 1.25, 95% CI 1.07–1.45, P = 0.004) but not with non-atopic asthma risk (OR = 1.28, 95% CI 0.97–1.68, P = 0.08).