ERBB2 and neoplasm: The percentage of PC-PLC-positive HER2-overexpressing cells (Figure 1c) was significantly higher (78% ± 13% in SKBr3; 61% ± 6% in MDA-MB-453; P < 0.001) than that of HER2-low tumor cells (MCF-7, 26% ± 7%; MDA-MB-231, 21% ± 15%; MDA-MB-435, 8% ± 3%) and nontumoral MCF-10A cells (<5% ± 2%).