ERBB2 and breast carcinoma: The effect of ErbB2 on BLNK was not unique to MCF10A cells since we found that while treatment of attached human ErbB2-positive breast cancer cells AU565, SKBR3 and BT474 [11] with the therapeutic anti-ErbB2 antibody trastuzumab does not upregulate BLNK protein (Fig. 1C–E, left), trastuzumab noticeably upregulates this protein when these cells are detached from the ECM (Fig. 1C–E, right).