ERBB2 and breast cancer: A phase 3 trial, called TULIP, randomized trastuzumab duocarmazine versus the physician’s choice (four choices in total: lapatinib and capecitabine, trastuzumab combined with either vinorelbine, capecitabine, or eribulin) in patients with metastatic HER2+ breast cancer who have progressed on two lines of HER2-directed therapy.