Acute Exacerbation According to GOLD 2017 Categories in Patients with Chronic Obstructive Pulmonary Disease Joohae Kim, Chang-Hoon Lee, Myung-Goo Lee, Kyeong-Cheol Shin, Kwang Ha Yoo, Seong Yong Lim, Ju Ock Na, Chul-Gyu Yoo, Ki Suck Jung, Sang-Do Lee

GOLD Staging System is Appropriate to Predict Mortality in Older People With Chronic Obstructive Pulmonary Disease Claudio Pedone, Renato Giua, Nicola Scichilone, Vincenzo Bellia, Raffaele Antonelli-Incalzi

Influence of the CYP2J2 Gene Polymorphisms on Chronic Obstructive Pulmonary Disease Risk in the Chinese Han Population Hui Lu, Yixiu Yang, Xianghong Chen, Cibing Wu, Jie Zhao, Qiong Feng, Xiaoli Zhou, Dongchuan Xu, Quanni Li, Huan Niu, Ping He, Jianfang Liu, Hongxia Yao, Yipeng Ding