In a pioneering trial, published in the same volume of Clinical Cancer Research, scientists from Merrimack Pharmaceuticals labeled MM-302 (HER2-targeted liposomal doxorubicin) with copper-64 (64Cu) and employed hybrid PET/CT to directly visualize tumor accumulation and therapeutic response in HER2-positive metastatic breast cancer patients. This evidence concerns the gene ERBB2 and neoplasm.