Concentrations of IL-4 (25.09 ± 1.53 pg/ml, 19.85 ± 2.06 pg/mL), IL-5 (8.76 ± 0.70 pg/ml, 12.68 ± 0.74 pg/mL) in plasma and BALF of mice in the TLR2-deficient mice group with asthma were significantly lower than that of wild-type group (P < 0.05), and had no significantly difference compared with control group (P > 0.05). Here, IL4 is linked to asthma.