Therefore, new PET tracers such as 89Zr-trastuzumab and 89Zr-pertuzumab were developed for measuring the HER2 expression of the primary tumor and metastases simultaneously in a non-invasive manner and have shown promising results in clinical studies; nevertheless, false-positive foci still remain a challenge to their effective utility (116, 135, 136). The gene discussed is ERBB2; the disease is neoplasm.