LILRB1 and B-cell chronic lymphocytic leukemia: Compared with healthy controls, the level of ILT2 expression on NK cells (Mean Fluorescence Intensity (MFI): 389.2 ± 217.8 vs. 717.9 ± 517.8, P < 0.01; Figure 1B) and the percentage of ILT2+ NK cells (4.2 ± 6 vs. 8.6 ± 9.1, P < 0.01; Figure 1C) were significantly increased in CLL patients.