EZH2 and B-cell chronic lymphocytic leukemia: In the CD19 + B-cells of CLL patients, the overexpression of SIRT1 and EZH2, global histone H3/H4 hypoacetylation, and H3 K9 hypermethylation were detected, which indicated that the abnormal histone modification played key roles in the pathogenesis of CLL [44].