IL4 and asthma: It has been commonly indicated that many cytokines shared by Th cell immune response and Treg cell immunosuppression are up-regulated in asthma, such as IL-4 (89, 90), IL-6 (91, 92), IL-9 (93, 94), etc. However, in asthma with high expression of these cytokines, the immune response of effector Th cells was activated as expected, but the immunosuppression of Treg cells did not seem to be properly activated.