In order to analyze the cytotoxicity of mPEG × HER2-modified PLD to HER2-overexpressed ovarian cancer cells, we incubated HER2+ SKOV-3 cells with different concentrations of PLD, mPEG × HER2− or mPEG × DNS-modified PLD for 12 h, followed by removing the drug, and washing the cells. This evidence concerns the gene ERBB2 and ovarian cancer.