HLA-E and B-cell chronic lymphocytic leukemia: CLL patients show a significant decrease in NK cell frequency in both the peripheral blood and lymph nodes [14] whilst NK dysfunction has been associated with upregulation of the NK cell inhibitory ligand HLA-E [15, 16], shedding of NK cell activating ligands [17, 18] and increased numbers of regulatory T cells and myeloid-derived suppressor cells [19].