ALK and lung cancer: In targeted therapy against lung cancer, many studies have focused on the more common non-small cell lung cancer (NSCLC) and involve inhibitors related to the epidermal growth factor receptor (EGFR) pathway, including the PI3K/AKT/mTOR and RAS–MAPK pathways, anaplastic lymphoma kinase (ALK), proto-oncogene ROS1, and programmed death 1 (PD-1) [7,8,9,10,11].