CD276 and cancer: Gratifyingly, using CD276-WT and -KO mice challenged with CD276 WT-or -KO cancer cells, we have been able to verify that CD276 ADC efficacy is largely target antigen dependent.14 However, studies with the same KO mice have helped illuminate a major limitation of our CD276 ADCs that likely also applies to many other ADCs across the field, that is, that ADC toxicities are predominantly driven by target-antigen-independent mechanisms.