The results showed that PAMPs recognized by TLR2 upregulated IL-10 and decreased the recruitment of pulmonary eosinophils, thus downregulating Th2 response.370,371 In allergic asthma, TLR9–IL-2 affects the Th2 response by regulating the expression of IL-17A, so small molecule inhibitors targeting TLR9 may become a new treatment strategy.372. This evidence concerns the gene TLR9 and allergic asthma.