In the neoadjuvant setting, the neoadjuvant study of pertuzumab and herceptin in an early regimen evaluation (NeoSphere) trial randomized 417 patients with centrally confirmed HER2-positive breast cancer to either docetaxel plus trastuzumab (HD, reference arm, n = 107), docetaxel, trastuzumab, and pertuzumab (HDP, n = 107), pertuzumab plus trastuzumab (HP, n = 107), or docetaxel plus pertuzumab (DP, n = 96). Here, ERBB2 is linked to breast cancer.