ERBB2 and breast carcinoma: Thereby, 5FE, 5FE2 and 5FE3, and F5E, F5E2 and F5E3 proteins all specifically interacted with ErbB2-positive cancer cells and UniCAR-expressing immune effectors, while no binding to ErbB2-negative MDA-MB-468 breast carcinoma cells used as a control and only background binding to parental NK-92 cells was found (Fig. 3).