IL15 and asthma: In lower airways, asthmatics also had significantly lower baseline IL-15 (ES: -0.69, <i>p</i> = 0.020) levels.<h4>Conclusion</h4>Overall, RV-induced asthma exacerbations are potentially caused by an imbalance between Th1 and Th2 cytokines, which may be contributed by defective innate immune responses at cellular levels.