ERBB2 and neoplasm: The patient's tumor was found to have low equivocal HER2 expression (IHC 2+/FISH-negative), and she was enrolled in a phase II clinical trial of fam-trastuzumab deruxtecan-nxki (T-DXd), an antibody-drug conjugate targeting the HER2 receptor (ClinicalTrials.gov identifier: NCT03505710).