Apart from HER-2 receptors, the glycoprotein non-metastatic melanoma protein b (GpNMB), epidermal growth factor receptor (EGFR), and ephrin A2 (EphA2) receptors have also been exploited, with formulations targeted to these receptors evaluated in breast cancer patients with HER-2-positive tumors. The gene discussed is GPNMB; the disease is breast cancer.