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]. Here, IL4 is linked to airway hyperresponsiveness.