Numerous studies also demonstrate trastuzumab’s efficacy in the early-stage setting, and the current standard-of-care treatment for patients with early-stage HER2-positive breast cancer is a combination of trastuzumab and cytotoxic chemotherapy with or without a second monoclonal anti-HER2 antibody, pertuzumab [3,4,5,6]. This evidence concerns the gene ERBB2 and breast carcinoma.