We demonstrated with an in vitro transendothelial cell migration assay that the treatment of HUVECs with LAMA84 exosomes induces LAMA84 migration through endothelial monolayer, likely due to a decrease of VCAM1-mediated adhesion of leukemia cells to EC and a concomitant chemotaxis toward serum. Here, VCAM1 is linked to leukemia.