Activation and adhesion receptors CD69, CD49d, and CD58, known for protecting cells from apoptosis and for associating with disease progression [28–30], were measured upon stimulation in four CLL samples previously identified as CLO-responding, and in three CLL samples that did not display any CLO-mediated protective effect (non-responsive). This evidence concerns the gene CD58 and B-cell chronic lymphocytic leukemia.