The Long Acting Beta Agonist Response by GEnotype (LARGE) study is the first protocol of ACRN II. It is a 60-week randomized, double-blind, cross-over study to compare the effects of long-acting beta-agonists in patients with asthma who are receiving inhaled corticosteroids and who express two distinct polymorphisms of the beta2-adrenergic receptor. The primary hypothesis is that those with the B16 Arg/Arg genotype will have worse asthma control, as defined by AM PEF rate, than those with the B16 Guj/Guj genotype. Recruitment started in December 2004 with a target of 80 randomized patients. See NCT00200967 for more information on this study.