Pertuzumab (PERJETA®, Genentech, Inc., South San Francisco, CA) is also an antibody that targets HER2 but because it targets a different subdomain of HER2 than trastuzumab, combined dosing results in a synergistic effect on the inhibition and survival of breast cancer cells [7, 8]. The gene discussed is ERBB2; the disease is breast carcinoma.