In this study, the proportion of ALK-positive nGGO lesions was significantly lower (2.8%) than that obtained in previous studies of a large cohort of adenocarcinomas (3.9-20.4%) (Table 6)[23,25,26,29-32], and was significantly lower than the 6.8% of 395 resected adenocarcinoma patients in our previous study, which included all types of curatively resected adenocarcinoma[23]. Here, ALK is linked to adenocarcinoma.