IL4 and asthma: The results showed significant association between IL-4 SNP (C33T) and asthma risk in Caucasians under dominant model (OR = 1.15, 95% CI = 1.04–1.28, P = 0.008, FEM), recessive model (OR = 1.17, 95% CI = 1.06–1.30, P = 0.002, FEM), allelic model (OR = 1.14, 95% CI = 1.07–1.22, P = ≤0.001, FEM),and CC vs. TT model (OR = 1.23, 95% CI = 1.01–1.49, P = 0.03, FEM) but not CT vs. TT model (OR = 1.1, 95% CI = 0.98–1.22, P = 0.09, FEM).