Aphase I clinical trial of [99mTc]Tc-(HE)3-G3(ClinicalTrials.gov Identifier: NCT05695859) at a dose of 3,000 μg showedthat it was safe for BC patients and highly specific in assessing the HER2/neustatus in the primary tumor using SPECT without CT [18]. The gene discussed is ERBB2; the disease is breast cancer.