In a trans-well co-culture system exosome-mediated transfer of MTA1 from MCF7 and MDA-MB-231 cells expressing GFP-CD63 and tdTom-MTA1 to ZR-75-1 (breast cancer cells) and EA.hy926 (vascular endothelial cells) was observed by fluorescent microscopy. This evidence concerns the gene CD63 and breast cancer.