ERBB2 and breast carcinoma: Finally, the trastuzumab-sensitive breast carcinoma cell line SKBR3 was treated with isotype control mAb, 10 nM lapatinib (as a positive control), 10 ug/mL HER2-BsAb or 10 ug/mL trastuzumab for 72 h and cell proliferation was assayed.