IL13 and asthma: Our results suggest that dupilumab acts on pathobiological mechanisms in severe asthma beyond those addressed by ICS specifically by blocking IL‐4 and IL‐13, cytokines that are broadly involved in type 2 inflammatory processes such as production and proliferation of Th2 cells, B cell class switching to immunoglobulin E (IgE) production, eosinophil and mast cell airway infiltration, airway fibrosis and remodeling, and mucus hypersecretion.18, 19, 20