Trastuzumab deruxtecan (DS-8201a) is a kind of ADCs and composed of a humanized anti-HER2 antibody, a potent topoisomerase I inhibitor (an exatecan derivative, DXd) and a tetrapeptide linker, which is stable in plasma and can be cleaved by cathepsin in tumor cells [13]. This evidence concerns the gene ERBB2 and neoplasm.