EZH2 and B-cell chronic lymphocytic leukemia: In order to explore whether the difference in cell viability could be attributed to EZH2 levels, we tampered with EZH2 expression in CLL cells from 3 EZH2high cases using an EZH2-specific siRNA and observed significant downregulation of EZH2 followed by a more modest downregulation of H3K27me3 levels (Figure 3D, 3E).