 - CEC will be enumerated using the consensual methodology based on an immunomagnetic separation assay 20. CEC will be isolated from EDTA whole blood using magnetic beads coated with antibodies directed against the CD146 antigen. Isolated cells will be identify using additional criteria such as morphology, size higher than 15μm, cell rosettes bearing more than 5 beads, and expression of endothelial markers lectin binding. 