FDA approval for the use of trastuzumab in the adjuvant setting was obtained in 2006, based on an interim analysis of two National Cancer Institute-Cooperative Group trials (NSABP 31 and NCCTG N9831) demonstrating remarkable prolongation of disease-free survival (DFS) with the addition of trastuzumab to chemotherapy in HER2-positive early breast cancer [3]. Here, ERBB2 is linked to breast cancer.