KLRK1 and B-cell chronic lymphocytic leukemia: Based on the evidence that CLL cells release high amounts of TGFβ, which has also been found in CLL patient serum [167], and that TGFβ reduces NKG2D expression on NK cells of healthy donors [166], it is plausible that TGFβ released by CLL cells represents a mechanism downregulating NKG2D expression on NK cells and consequently impairing NK cell activity.