Figure. Summary of plausible biological mechanisms underlying genes associated with asthma exacerbation. (A) Genes related with gene-environment interactions and asthma pathogenesis. (B) Genes related with pharmacogenetic effects. β₂AR, β₂-adrenergic receptors; CysLTR1, cysteinyl leukotriene receptor 1; GC, glucocorticoid; GR, glucocorticoid receptor; LTC4, leukotriene C4.