Based on these studies, a window-of-opportunity trial examined adaptive changes in women with HER2+ breast cancer in response to current standard-of-care anti-HER2 therapies: trastuzumab, pertuzumab, trastuzumab + pertuzumab, and trastuzumab + lapatinib (ClinicalTrials.govNCT01875666). Here, ERBB2 is linked to breast cancer.