Levels of IL-9 and IL-4 in children with allergic asthma(30.23 ± 1.92 pg/ml and 25.81 ± 2.14 pg/ml, respectively) were significantly higher than those in healthy children (67.37 ± 9.27 pg/ml and 49.50 ± 9.99 pg/ml, respectively) (Fig. 1a and c). Here, IL4 is linked to allergic asthma.