The main purpose of chemotherapy however is to reduce the risk of recurrence of cancer and also make surgery more successful. HER2 is a receptor located on the surface of some cells. This receptor plays a role in regulating the growth of the cell, in addition to the growth of tumors. High levels of the HER2 receptor may predict those women who benefit from treatment with agents such as Herceptin that target HER2. Herceptin (Trastuzumab) is a drug that is effective both alone and in combination with standard chemotherapy. There is some data to suggest that patients whose tumors have low expression of the HER2 protein and are normal by FISH may also receive benefit from Herceptin.