To explore the mechanism by which CpG-ODNs treatment regulates the cytokine IL-17 A due to HDAC2 upregulation, we next examined the levels of RORt, which is an important biomarker of the HDAC2-mediated Th17 response in CS-induced asthma, by immunohistochemistry, ELISA and Western blotting. This evidence concerns the gene HDAC2 and asthma.