It became the foremost HER2-targeted therapy accepted for treating HER2-positive breast cancer.[8,9] The combined use of HER2-targeted therapy with chemotherapy, particularly with taxanes, is well established and improves the progression-free survival and overall survival of patients.[10,11] Considering the widespread prevalence of HER2-positive breast cancer, urgent action is needed to devise therapeutic methods. This evidence concerns the gene ERBB2 and breast cancer.