Obeidat M, Faiz A, Li X, et al. - In order to find out the genetic determinants for forced expiratory volume in 1 s (FEV₁) alterations associated with inhaled corticosteroids (ICS) therapy in patients with COPD, researchers analyzed 802 genotyped participants from the Lung Health Study 2 (LHS-2)—a study including 1,116 COPD patients randomized to the ICS, triamcinolone acetonide (n = 559), or placebo (n = 557)— in a pharmacogenomic genome-wide association study. In COPD patients (n = 199) randomized to the ICS, fluticasone or placebo, they performed replication. At P < 5×10⁻⁶, genotype-by-ICS interaction was displayed by 5 loci. Among these, replication of SNP rs111720447 on chromosome 7 (discovery P = 4.8×10⁻⁶, replication P = 5.9×10⁻⁵) was seen with the same direction of interaction effect. A significant link of genotype at SNP rs111720447 with the rate of FEV₁ drop was revealed in patients receiving ICS and also in patients treated with placebo, in the stratified analyses of LHS-2. However, the link was found to be weaker and was in the opposite direction compared with that in the ICS group.