摘要Introduction Cancer treatment has been revolutionized with the advent of targeted therapy and immunotherapy. In the past, when cancer treatment modalities were restricted, conventional chemotherapy was the only option for systemic disease. Because chemotherapy empirically affects all dividing cells, the targets are virtually non-specific. In this regard, toxic effects on normal tissue are essentially inevitable. Historically, oncologists prescribed chemotherapy accord-ing to the patient's clinical characteristics, including cancer type, histology, and stage. As a result, all cancer patients who shared the same clinical diagnosis were treated similarly. In contrast, targeted therapy and immunotherapy are designed to tackle specific targets. This selectivity minimizes the undesired off-target effects, while enhancing efficacy. With breakthrough discoveries in molecular cancer biology, oncol-ogists now individualize these novel therapies with precision for each patient based on predictive biomarkers. One of the well-established and clinically relevant biomarkers is a genetic alteration in cancer cells1.