The plasma exosomes of CLL patients mainly expressed the surface markers CD37, CD63, and CD9, but not CD3, CD56, and CD41, suggesting the genesis of these exosomes from B-lymphocytes and not from T-lymphocytes or other blood cells [67], confirming the promising role of exosomes in monitoring hematological tumors. This evidence concerns the gene CD63 and B-cell chronic lymphocytic leukemia.