NSCLC specimens (n=150) and corresponding adjacent nonlung cancer tissues (n=150 were collected from 3 medical centers: Korea University Guro Hospital (40 samples from 20 patients), Pusan University Hospital (140 samples from 70 patients), and Jeonbuk National University Hospital (120 samples from 60 patients). We also collected basic clinical data for the NSCLC patients, including age, sex, histological type, cancer stage and smoking status (Table 1). All frozen specimens were collected after informed consent was obtained, and this study was approved by the Ethics Committee of Hallym University of Korea (HIRB-2016-018-6-RMMMC-C-C).