The rapid evolution of treatment for advanced lung cancer is a story of how scientists have struggled to move from nonselective cytotoxic chemotherapy to personalized precision medicine. In this century, extraordinary advances have been made in the management of advanced and metastatic non–small cell lung cancer, especially in the development of small molecules targeting specific tyrosine kinase receptors and immune checkpoint inhibitors. These developments have led to a significant improvement in survival for lung cancer patients with metastatic disease. Now, the core guidelines to treat non–small cell lung cancer are based on the identification of targetable driver mutations and immune checkpoints. Continued investigations of newly identified druggable genetic alterations, explorations of biomarkers of immune checkpoint inhibitors, development of next-generation immunotherapy, and optimization of combination therapy are necessary to provide better treatment outcomes for lung cancer patients in the future.