ALK and adenocarcinoma: Previous studies have reported that 10–20% of Caucasian and at least 50% of Asian non-squamous NSCLC patients harbored activating EGFR mutations [1–4], and the high absolute number of ALK-positive NSCLC patients, mainly with the adenocarcinoma subtype, was due to 3–7% of NSCLCs harboring ALK rearrangements [5].