ERBB2 and breast cancer: Javier Corte et al. reported that HER2‐positive breast cancer patients whose disease progressed during prior trastuzumab‐based therapy, the ORR and DCR were 3.4% and 10.3%, respectively, during pertuzumab monotherapy, with the addition of trastuzumab, the ORR and DCR were 17.6% and 41.2%, respectively.22