IL‐5 is essential for the recruitment and survival of eosinophils, while IL‐4 may contribute significantly to phenotypic or functional changes in asthma, such as airway hyperresponsiveness, eosinophil infiltration, and mucus overproduction, potentially exacerbating airway inflammation [2, 22, 34, 35]. This evidence concerns the gene IL5 and airway hyperresponsiveness.