Specifically, mPEG and trastuzumab (Herceptin®, HER), a humanized antibody that targets Her-2 and is used in combination with chemotherapy to treat patients with Her-2-overexpressing breast cancers, were attached to the surfaces of PGNSs via electrostatic interactions [42] and Au–S bonds [43]. This evidence concerns the gene ERBB2 and breast carcinoma.