EZH2 and B-cell chronic lymphocytic leukemia: We found that in contrast to the CLL cell line I83-E95, in patients valproate transiently recruited the transcriptional repressor EZH2 and simultaneously induced the repressive histone mark H3K27me3 and the activating mark H3K9ac on the CD20 promoter in del13q/NOTCH1wt CLL in vivo, suggesting that valproate may induce a bivalent status of the CD20 promoter in vivo.