ERBB2 and neoplasm: While some of the mechanisms of action of ADC targeting HER2 are shared with the unconjugated (i.e., naked) trastuzumab mAb (e.g., the capability to induce strong NK-mediated antibody-dependent cell death (ADCC) of tumor cells expressing the HER2 target) [2], others, such as the ability to internalize a highly cytotoxic payload (i.e., chemotherapy) specifically into tumor cells expressing the specific biomarker, are unique to ADCs [8,9].