Trastuzumab‐Deruxtecan (T‐DXd, Enhertu), a HER2 antibody linked to a topoisomerase inhibitor by means of a cleavable linker (Fig. 1) takes use of this principle, and unlike conventional anti‐HER2 therapies, T‐DXd has shown improved patient outcomes compared to physicians' therapy of choice in patients with metastatic breast or gastric cancer with low immunohistochemical (IHC) expression of HER2 [8, 9]. This evidence concerns the gene ERBB2 and gastric cancer.