In human CLL samples, we observed an even more dramatic downregulation of CD1d, reflected in a significantly higher CD1d negative cell fraction as well as decreased MFI for CD1d in patients compared to healthy volunteers (Figure 4D and Supplementary S2, CD1d negative cells: 8.0% ± 3.2% vs 63.2% ± 24.8%, Mann Whitney test p < 0.0001). This evidence concerns the gene CD1D and B-cell chronic lymphocytic leukemia.