What is meant by individualized therapy? In recent years, pharmacogenetics/pharmacogenomics has gained breakthroughs in the research of chemotherapeutic drug mechanism of action, etc. It has been found that the killing effect of chemotherapeutic drugs on tumor cells is significantly associated with the expression and/or polymorphism of a specific type (group) of genes. The detection of relevant genes to predict the efficacy of chemotherapeutic drugs and to select appropriate drugs for individualized chemotherapy has become a reasonable choice to improve the efficacy and reduce ineffective treatment. Individualized chemotherapy is a method of chemotherapy using specific and optimal chemotherapeutic drug regimens based on the pharmacogenetic and pharmacogenomic characteristics of cancer patients. Individualized chemotherapy can help patients choose the right chemotherapy drugs, improve the targeting of treatment, and maximize survival. What are the advantages of individual chemotherapy? A large amount of clinical data shows that mRNA expression levels of ERCC1/RRM1/TYMS/TUBB3 and other target genes in tumor tissues can predict patients’ response to platinum/gemcitabine/fluorouracil/anti-microtubule chemotherapy drugs, respectively. Based on the results of mRNA expression levels in patients’ tumor tissues, individualized treatment plans can be developed, which can help to select suitable chemotherapeutic drugs for patients and improve the targeting of treatment. Selecting chemotherapy drugs through target testing can avoid ineffective and harmful chemotherapy, save valuable treatment time and improve patients’ quality of life. Chemotherapy is an indispensable and important tool in comprehensive cancer treatment? Chemotherapy is a method of treating cancer with drugs. These drugs are often referred to as chemotherapeutic agents or anticancer drugs, which can directly destroy and kill cancer cells. In the past 50 years, due to the rapid development of anti-tumor drug therapy and the updated concept of clinical treatment, chemotherapy has made many significant achievements and become one of the methods to eradicate tumors, which is an indispensable and important tool in the comprehensive treatment of common tumors. Is chemotherapy always effective for cancer patients? Not necessarily! Clinical results show that only thirty to forty percent of patients benefit from each chemotherapy regimen. The efficacy of chemotherapy is related to individual patient differences (how sensitive the patient is to the chemotherapy drug and how well the drug is tolerated) and the toxic reactions of the drug itself. Therefore, chemotherapy for tumors requires consideration of the interrelationship between the drug, the tumor and the individual. It is impractical to increase the efficacy of chemotherapy by increasing the dose of the drug alone, and the aggravation of drug toxicity will force doctors to delay or terminate chemotherapy. The efficiency of chemotherapy for tumors is often not high when the drugs are selected based on clinical experience alone.