In an alternative study on human epidermal growth factor receptor 2 (HER2)-specific CAR-NK cells against HER2-expressing malignancies, HER2 CAR-NK cells demonstrated stronger cytotoxicity than HER2 CAR-T cells without on-target off-tumor effects, and maintained their cytotoxic activity in the immunosuppressive microenvironment (14). The gene discussed is ERBB2; the disease is neoplasm.