A 45-yeаr-оld wоmаn presents tо the emergency depаrtment with bone pain and a mass over the distal right femur. Radiography shows a large lobulated, exophytic, cauliflower-like mass with dense central ossification and a thin radiolucent “string sign” separating the tumor from the underlying cortex. She is diagnosed with parosteal osteosarcoma. Which CRISPR–Cas–engineered natural killer (NK) cell modification is most likely to improve antitumor activity in this patient?