In addition, our analyses of GITR/GITRL and 4-1BB/4-1BBL expression on CLL patients’ NK and T cells revealed pronounced expression of GITR and 4-1BB on NK cells of CLL patients, whereas GITRL and 4-1BBL were only very weakly expressed. This evidence concerns the gene TNFRSF18 and B-cell chronic lymphocytic leukemia.