CD63 and breast cancer: In line with the strategy of eliminating circulating cancer sEVs, a recent report demonstrated, in a xenograft nude mouse model, that treatment of the mice with human anti-CD9 and anti-CD63 antibodies (intravenous injection) disrupts cancer sEVs in the circulation and suppresses the pulmonary metastasis of implanted human breast cancer cells, yet, has no effect on primary tumor growth of the implants or metastatic ability of the cells in vitro [102].