EPS15, CCT7, SRPRB, and STRN4 are involved in receptor endocytosis and the turnover of β2-adrenergic and M3-muscarinic receptors critical for bronchial constriction and airway hyperresponsiveness as well as signaling through TGF-β and β1-integrins linked to eosinophil recruitment [58] and airway wall structural changes. This evidence concerns the gene STRN4 and airway hyperresponsiveness.