ADRB2 and asthma: Figure 1 summarizes the crosstalk between the genes covered in this review, constructed with STRING (Szklarczyk et al., 2017), and the major associations identified with asthma therapy. Three major clusters appear, including one related to leukotrienes, another that includes CRHR genes (related with inhaled corticosteroids), and ADRB2 and ADCY9 (related with beta-agonists), and a third cluster related to drug-metabolizing enzymes and transporters.