Finally, molecules such as CD16, NKG2D, and CD28, which are essential for the control and elimination of myeloma, were highly expressed in all the patient material analyzed, indicating that neither Len nor Len+Dex prolonged treatment at first relapse reduces either the expression or, potentially, the activity of these cells 16, 17, 18, 19. This evidence concerns the gene KLRK1 and plasma cell myeloma.