ERBB2 and ovarian cancer: Similarly, our mPEG × HER2-modified PLD exhibited higher endocytic ability (Fig. 2) and cytotoxicity (Fig. 3) in HER2-overexpressed ovarian cancer cells changing the IC50 from 870 to 160 ng mL−1 and significantly improving the therapeutic efficacy of SKOV-3-xenografted nude mice with minimal obvious toxicity (i.e. no significant body weight changed) as compared with non-targeted control BsAb-modified PLD (Fig. 5).