IL4 and chronic obstructive pulmonary disease: IL-4 showed significant differences in the comparison with the carrier of genotype AA vs. AG or GG for patients with COPD (111.2 pg/mL vs. 94.2 pg/mL), and the same trend was observed in SWOC group AA vs. AG+GG (81.2 pg/mL vs. 67.8 pg/mL; p = 0.035) (Figure 2H).