In a preclinical study, MAEE-linked anti-B7-H3 antibody–drug conjugates (ADCs) displayed a dose-dependent antitumor activity against B7-H3+ tumor cells in HCT-116, KM12, and HT29 colon, OVCAR3 ovarian, and MDA-MB-231 breast tumor xenografts. This evidence concerns the gene CD276 and breast neoplasm.