IL4 and asthma: Although the nature of the mediators capable of altering ASM response to GC in our study has not been investigated, a number of cytokines (TNFα, IFNγ, IL-17, IL-4, IL-13, macrophage migration inhibitory factor), alarmins (TSLP), growth factors (TGFβ) produced by activated mast cells have been shown to dampen GC response when tested individually in other asthma relevant cells [reviewed in (3)].