The number of treatments of targeted drugs is related to the whole treatment modality. Let’s say postoperative adjuvant chemotherapy, at present, for breast cancer with positive HER2 expression, it has a certain number of treatments, let’s say 4 times, 8 times, the number of times is specified and limited. But for some advanced tumor patients, targeted therapy as long as the benefit, if there is no serious toxic side effects, usually encourage patients to maintenance therapy. That is to say, after the use of targeted drugs, for patients with advanced tumors, if there are no serious toxic side effects, if there is no discontinuation of drugs due to failure of drug therapy, patients are encouraged to carry out continuous maintenance therapy. Of course, continuous maintenance medication is also required to carry out the relevant dose adjustment, relevant program changes, the purpose is not only to maintain, consolidate the existing therapeutic effect, but also to prevent the emergence of some of the relevant possible toxic side effects of the targeted drugs. That is to say, the cycle of drug use is defined according to the efficacy, according to the side effects, especially in advanced patients.