LILRB1 and B-cell chronic lymphocytic leukemia: Lenalidomide also decreases the expression of NK cell inhibitory receptors, such as Ig-like transcript 2 (ILT2), which is profoundly dysregulated in CLL [119,120], and decreases both the expression of both PD-1 on NK cells and its ligand, programmed death-ligand 1 (PD-L1), on tumor cells [117].