ERBB2 and neoplasm: Moreover, micro-PET imaging and biodistribution studies of 124I-trastuzumab were considered in order to examine the compound’s specificity in HER2-positive and HER2-negative mouse models, and as a result, the authors observed elevated tumor uptake levels of 124I-trastuzumab when compared with 124I-IgG1 in HER2-positive mouse models.