,20 In allergic asthma, we and others have shown temporal21 and cell-specific requirement of IL-4Rα in dendritic cells,22 T cells,23 and epithelial cells24 and also the redundant role of this IL-4/IL-13 signaling receptor in macrophages25 and airway smooth muscle cells.26 This evidence concerns the gene IL4 and allergic asthma.