In 1998, Trastuzumab (marketed as Herceptin, Genentech, San Francisco, California, USA) was approved for the targeted therapy of HER2-overexpressing metastatic breast cancer patients by the Food and Drug Administration (FDA) of the USA, and it has also recently been shown to be very effective in the adjuvant setting [2]. Here, ERBB2 is linked to breast carcinoma.