For example, sacituzumab govitecan (Trodelvy) targets trophoblast cell surface antigen 2 (Trop-2) in triple-negative breast cancer, belantamab mafodotin (Blenrep) targets B-cell maturation antigen (BCMA) in multiple myeloma, and trastuzumab deruxtecan (T-DXd) targets human epidermal growth factor receptor 2 (HER2) in breast cancer [35,36,37,38] while researchers are developing engineered ADCs to efficiently penetrate tumour tissues and deliver cytotoxic payloads to cancer cells. The gene discussed is ERBB2; the disease is breast carcinoma.