The results of genetic testing are needed to determine whether targeted therapy can be administered and the drugs to be used for targeted therapy. In addition, some targeted drugs may not require genetic testing. Most tumors are driven by a driver gene. If the driver gene can be found and blocked, the tumor cells will not grow, which is the principle of targeted therapy. This is the principle of targeted therapy. Genetic testing can be used to screen for mutated genes and select the most appropriate targeted drug for the mutated gene. After the target gene is screened out, the targeted drug treatment can effectively inhibit the malignant proliferation of the tumor, slow down the growth of the tumor and shrink the tumor lesions, which has a very obvious effect on the prognosis of the disease. Targeted therapy will be accompanied by diarrhea, rash, nausea, vomiting and other adverse reactions. It is recommended that patients standardize the treatment under the guidance of doctors and do not use drugs on their own.