In a recent study evaluating the usefulness of 89Zr-labeled trastuzumab for detecting tumor lesions in breast cancer patients, Dehdashti et al. found that 89Zr-trastuzumab was unable to discriminate effectively between HER2-positive and HER2-negative lesions in the liver; moreover, lesion uptake was similar to radioactivity levels observed in the normal liver [39]. This evidence concerns the gene ERBB2 and neoplasm.