Since the addition of taxanes to anthracycline-based adjuvant treatment schedules improved the outcome of breast cancer patients in general, regimens for HER2-positive breast cancer patients were developed where trastuzumab was started sequentially after the anthracycline-based part of the regimen and concurrently with a taxane [2, 29, 30]. The gene discussed is ERBB2; the disease is breast carcinoma.