IL4 and airway hyperresponsiveness: Relative to mice challenged with fungal spores and vehicle, salmeterol enhanced the number of total lung cells secreting IL-4 and IL-17A, cytokines that are produced in part by TH2 and Th17 cells, respectively, and which contribute to the expression of both lung inflammation and airway hyperresponsiveness [17, 26, 46] (Fig 1e and 1f).