Currently, research has shown aspects of cellular uptake in breast cancer cell lines [15], but a study that simultaneously compares the similarities and differences in HER2-positive (SKBR3) and HER2-negative (MCF7) cytotoxicity, cellular uptake, distribution, and endocytosis mechanisms of bare gold nanorods is not available in the literature to compare with our results. The gene discussed is ERBB2; the disease is breast carcinoma.