ERBB2 and gastric cancer: In addition, BT‐474 (HER2+ breast cancer), MDA‐MB‐231 (breast cancer) and AGS (gastric cancer) also demonstrated enhanced NK cell‐mediated cytotoxicity, with one donor (#2 for BT‐474, #8 for MDA‐MB‐231 and #3 for AGS) surpassing NK‐92 in cytotoxic efficiency.