ERBB2 and neoplasm: To determine whether the bsAb could induce human T cells to kill HER2-positive tumor cells, we co-incubated effector T cells with different target cells in the presence or absence of serially diluted HEK293S medium containing the secreted HER2-CD3-Fc bsAb and monitored target cell viability using the impedance-based xCELLigence real-time cell analysis (RTCA) system.