EGFR and lung adenocarcinoma: ALK gene rearrangement occurs in a small portion of patients with non-small-cell lung cancer (NSCLC) [5], but it accounts for about 30%–40% of lung adenocarcinoma in young individuals, and is present in many non-smokers and patients with epidermal growth factor receptor (EGFR)-mutated lung cancer [6,7,8].