The most recent analysis of the CLEOPATRA data was reported by Swain and colleagues (2015) to answer two critical questions: (1) Does adding a second, different monoclonal antibody for HER2 to trastuzumab plus docetaxel chemotherapy increase overall survival in patients who have metastatic, HER2-positive breast cancer without increasing the burden of treatment (adverse effects)? Here, ERBB2 is linked to breast cancer.