ALK and lung cancer: Targeted therapeutic agents such as epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) and anaplastic lymphoma kinase (ALK) inhibitors, as well as immunotherapeutic drugs targeting programmed cell death protein 1 or programmed death-ligand 1 (PD-L1), have changed the treatment of lung cancer and provided other treatment options for patients with advanced and refractory lung cancer [7, 8].