However, loss of ADCC activity for trastuzumab treatment was also noted in patients with metastatic HER2pos BC.50 DC vaccine therapy in patients with HER2pos metastatic BC elicited production of specific anti-HER2 antibodies and CD4 Th1 immunity resulting in complete response.51 Our study identified that combination treatment with HER2-DC1 i.t. and anti-HER2 antibodies induces ADCC for the enhanced antitumor response, supported by the failure to block tumor aggression and to induce complete tumor growth arrest in a FcγR KO model. Here, FCGR2A is linked to breast cancer.