Following this success in the metastatic setting, ongoing evaluation of trastuzumab in adjuvant settings for operable HER2-positive breast cancers was started, and with the six randomized phase III trials of the integration of trastuzumab into standard adjuvant treatments completed to date, all but one reporting that the addition of trastuzumab provided a significant improvement in efficacy [9–16]. Here, ERBB2 is linked to breast cancer.