Altogether, these data show that CCL2 binding to BC exosomes alters their systemic biodistribution as well as cell lineage-specific vesicle uptake, and likely contribute to the pro-metastatic changes induced in distal organs by TIF-conjugated BC exosomes (Fig. 3 and Supplementary Figs. 5 and 6), thereby facilitating BC metastasis (Fig. 6). This evidence concerns the gene CCL2 and breast cancer.