ERBB2 and cancer: While less development has been done on VLP-based cancer vaccines, one notable target that has been used is the widely expressed cancer antigen human epidermal growth factor receptor-2/neu (HER2), which has shown to be immunogenic in mouse models (237–244) and in early clinical testing in humans (245) and dogs (246), but as a whole these vaccines have had to undergo additional design in order to overcome B cell tolerance (227, 247) and to fully characterize their anti-tumor activity.