IL4 and cancer: A significant association between IL-4-590C/T variant and the susceptibility of the smoking-related cancer in Asian population (CT vs. TT: P=0.008, OR = 0.878, 95% CI: 0.798–0.967; CC + CT vs. TT: P=0.030, OR = 0.903, 95% CI: 0.824–0.990) was found.