Combining an inhaled corticosteroid (ICS) with a long-acting β2-adrenoceptor (β2-AR) agonist (LABA) is the cornerstone for the treatment of adult patients with asthma symptoms when a medium dose of ICS alone fails to achieve control of asthma [1].The scientific rationale for inhaled combination therapy with β2-AR agonists and corticosteroids has been debated for a long time [2]. This evidence concerns the gene ADRB2 and asthma.