In recent years, there has been a boom in individualized tumor treatment. The direction of cancer treatment is gradually changing – on the basis of advocating standardized treatment, emphasis is placed on personalized treatment for different patients and selecting the most likely effective drug treatment for patients, i.e. individualized treatment for tumors. And now with the progress of molecular oncology and molecular genetics research, endless new technologies and methods have made it possible to personalize treatment for tumor patients. Currently, chemotherapy remains the main weapon of systemic antitumor therapy. With the progress of pharmacological research, more and more chemotherapeutic drugs are entering the clinic, bringing clinical benefits to many tumor patients. However, as cytotoxic drugs, side effects of chemotherapy drugs are inevitable, and many patients have to suffer from chemotherapy side effects. Even so, in clinical practice, we find that most chemotherapeutic agents are still ineffective and many patients have developed primary or secondary resistance to chemotherapy. If the most potentially effective drug can be selected for chemotherapy, patients can avoid experiencing the toxic side effects of needless chemotherapy. Therefore, current chemotherapy for oncology advocates individualized treatment. On the other hand, the emergence of molecular targeted therapies is a milestone in the field of tumor treatment in recent years, and highly efficient and low-toxic targeted drugs have brought improved quality of life and survival to more and more tumor patients. However, it is the targeted nature and high selectivity of targeted drugs that make the selection of patient population for targeted therapy particularly important. For example, if an EGFR inhibitor (Epiduo) is used to treat metastatic colorectal cancer, adding Epiduo to chemotherapy will not increase the efficacy of the treatment if the patient has a K-ras mutation, but will cause the patient to experience additional side effects of Epiduo. In addition, most targeted drugs are currently expensive, and it is more in line with health economics to select patients who are most likely to benefit from molecularly targeted therapy. Therefore, molecularly targeted therapies need to be individualized. Advances in molecular oncology and molecular genetics have made individualization of tumor therapy possible, and many biomarkers (or genetic markers) have been identified that are closely related to the efficacy of antitumor therapy. Clinical oncologists are also exploring the application prospects of these markers for clinical application in predicting the efficacy of antitumor therapy, and some of them have been successfully applied in clinical practice, while some of them are yet to be clinically validated in large quantities. In conclusion, the 21st century is the era of individualized tumor therapy, and the strategy of antitumor therapy has been converted from “seek and destroy” to “target and control” in the past, and choosing the most appropriate therapy for the right patient to obtain the highest possible efficacy and the lowest possible side effects has become the current trend of antitumor therapy. The selection of the most appropriate treatment for the right patient, the highest possible efficacy and the lowest possible side effects have become the basic requirements of current antitumor therapy, and the discovery of effective efficacy predictive markers has accordingly become a critical clinical problem to be solved in the field of individualized tumor therapy.