CD4 and asthma: CsA has been shown to improve lung function and inhibit airway inflammation, such as lymphocytic and eosinophilic infiltration, and Th2 cytokine production [26], suppress IL-17 production in CD4+ T cells through the inhibition of PI3K/Akt and NF-kB [27], and has a well-established clinical efficacy for the improvement of lung function in severe asthma; therefore, we used CsA and rosiglitazone as positive controls.