Drug conjugates with Trastuzumab are new approaches for HER2-expressing cancer, for example, Enhertu was FDA approved in 2022 for second-line treatment of breast cancer (Hurvitz et al., 2023); it was also approved for certain gastric and lung cancers (Li et al., 2022; Rha and Chung, 2023). The gene discussed is ERBB2; the disease is cancer.