ERBB2 and cancer: Trastuzumab isa monoclonal antibody that is clinically used to treat Her2 positivebreast cancer by binding to a conformational epitope of Her2 proteinin its extracellular juxtamembrane domain and blocking its function.In our previous study, we have demonstrated that 4C5-8 binds to cell-freeproduced Her2-NLP similar to native Her2 protein,5 and in the current experiment, we observed no effect ofeither empty NLPs or Her2-NLPs in combination with Her2-targeted antibodythat blocks the receptor function (Figure 1F).