Our results showed that a one-step formulation of mPEG × HER2 BsAbs with multiple PEG-NPs (liposome, Qdot, AuNP and SPIO) could enhance the HER2 targeting ability of PEG-NPs to HER2-positive tumor cells compared with untargeted PEG-NPs. The gene discussed is ERBB2; the disease is neoplasm.