[1] Sungkyunkwan Univ, Samsung Biomed Res Inst, Dept Mol Cell Biol, Sch Med, Suwon 440746, South Korea
[2] Inje Univ, Ilsan Paik Hosp, Dept Internal Med, Div Pulm & Crit Care Med, Goyang, South Korea
[3] CHA Univ, Coll Med, Dept Internal Med, Div Pulm & Crit Care Med, Songnam, South Korea
[4] Univ Ulsan, Asan Med Ctr, Coll Med, Dept Lab Med, Seoul, South Korea
[5] Univ Ulsan, Asan Med Ctr, Coll Med, Dept Pulm & Crit Care Med,Asthma Ctr, Seoul, South Korea
[6] Univ Ulsan, Asan Med Ctr, Coll Med, Clin Res Ctr Chron Obstruct Airway Dis, Seoul, South Korea