AXL and B-cell chronic lymphocytic leukemia: Plasmatic microvesicles of CLL patients that originated from B-cells carry a constitutively phosphorylated RTK AXL.48 Microvesicles circulating in plasma of B-cell CLL patients exhibit a phenotypic shift from predominantly platelet-derived microvesicles, at an early stage, to leukemic B-cell-derived ones at an advanced stage.