The comparison was performed with another HER2-targeted radiopharmaceutical being tested in clinical trials ([131I]SGMIB-2Rs15d); 2Rs15d was the first anti-HER2 NB used as a targeted radionuclide agent for the treatment of HER2+ breast cancer, with tumor targeting, biodistribution, and safety evaluated in a pre-clinical investigation before moving on to a phase I clinical trial [87]. The gene discussed is ERBB2; the disease is breast cancer.