Target Therapy is the medications that are classified into a new class, such as Anti-HER2 medications which function differently from other former classes of medications. Breast cancer cells in some patients have Hertu receptors on the cell surface. This makes it possible to use the medications to bind to these receptors and allow the medications to destroy cancer cells. Therefore, other cells without a receptor will not be affected by these medications. However, even if they are effective drugs, the treatment is quite specific. Even though there are fewer side effects than chemotherapy medications, there are limitations that can only be applied to certain patients. In addition, the medications are very expensive. The use of these kinds of medication is not very widespread and the patient should consult the doctor about the use of medication in detail.