This observation is supported by studies showing that interaction between the glucocorticoid-induced TNFR-related protein (GITR) receptor and its ligand (GITRL) expressed at high levels in NK cells of CLL patients and CLL cells, respectively, induces in the latter the release of TNF, IL-6 and IL-8 [205], which are known to act as autocrine/paracrine growth and survival factors for CLL cells [206,207,208]. The gene discussed is IL6; the disease is B-cell chronic lymphocytic leukemia.