The most widely used drug based on this principle is Trastuzumab (Herceptin®, Genentech Inc., San Francisco, CA, USA), a high-affinity humanized anti-Her-2 antibody that was shown to benefit patients with Her-2-overexpressing breast cancer, either as a single agent or in combination with chemotherapy [6,11,12]. Here, ERBB2 is linked to breast carcinoma.