ERBB2 and breast cancer: The selectivity of simvastatin immunoliposomes was confirmed on breast cancer cell lines which differ in terms of HER2 expression: BT474, SKBR3 (high expression of HER2) and MCF7, MDA MB 231 (low expression of HER2), using two independent methods, flow cytometry (Figure 6A) and confocal microscopy (Figure 6B).