The results of the recent NSABP B-31 trial comparing the safety and efficacy of doxorubicin and cyclophosphamide followed by paclitaxel (AC-T) to that of AC-T plus trastuzumab suggested that some patients with HER2− cancer benefited as much from HER2-targeted adjuvant trastuzumab as patients with HER2+ [6]. Here, ERBB2 is linked to cancer.