LILRB1 and B-cell chronic lymphocytic leukemia: We noticed that the conjugation rate of primary CLL cells with NK-92MI cells was particularly low (~7% of all CD5+/CD19+ cells; Figure 5C), which can be explained by a high surface expression of HLA-G on ex vivo CLL cells (40) and expression of the cognate inhibitory receptor immunoglobulin-like transcript 2 (ILT-2, LILRB1) on NK-92MI cells (66).