ERBB2 and breast cancer: To examine the potency of ACE-oNK-HER2 to HER2+ cancer cells, ACE-oNK-HER2 were co-incubated with SK-OV-3 (ovarian cancer), SK-BR-3 or MCF-7 (breast cancer) cells and the cytotoxicity was measured by the xCELLigence real-time cell analysis system.