ERBB2 and cancer: Though trastuzumab and pertuzumab might be less effective in cancers with HER2-low, antibody-drug conjugate (ADC) such as trastuzumab emtansine (T-DM1) and trastuzumab deruxtecan (T-Dxd) could still be effective as long as the agent could bind with the HER2 receptor releasing emastine or deruxtecan to cause cell kill.