ERBB2 and breast cancer: Incorporation of new agents, as evidenced by the CLEOPATRA trial, in which pertuzumab, a humanized monoclonal antibody that binds to HER2 at a different epitope than that at which trastuzumab binds, was added to the standard docetaxel and trastuzumab combination, and lead to striking improvements in PFS and OS in a cohort of advanced HER2+ BC patients, reaching the median OS boundary of almost 5 years.