ERBB2 and B-cell acute lymphoblastic leukemia: To date, nine ADCs targeting human epidermal growth factor receptor-2 (HER2), CD22, CD30, CD33, CD79B, Nectin-4, and Trop-2 are clinically available for the treatment of HER2-positive metastatic breast cancer, B-cell acute lymphoblastic leukemia, Hodgkin’s lymphoma, acute myeloid leukemia, B-cell lymphoma, bladder cancer, and triple-negative breast cancer, respectively44.