ERBB2 and aneurysmal bone cyst: Recently, the antibody-drug conjugate (ADC) Trastuzumab-deruxtecan (T-DXd) significantly improved progression-free survival (PFS) and overall survival (OS) when compared with standard chemotherapy in pre-treated patients with HER2-low advanced BC (aBC), the majority of whom had HR + /HER2-low aBC10.