EML4 and lung adenocarcinoma: In NSCLC, particularly in lung adenocarcinoma, molecular target drugs, including epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) (12), the vascular endothelial growth factor (VEGF) targeting monoclonal antibody (12), and the echinoderm microtubule-associated protein like 4-anaplastic lymphoma kinase (EML4-ALK) inhibitor, have emerged rapidly (38).