IRE1 promoter in GCB DLBCL carries high levels of repressive histone mark H3K27me3. (A) Correlations as measured by the Pearson correlation coefficient r between EZH2 expression and IRE1 expression in GCB DLBCL clinical samples from 2 data sets extracted from GSE10846. (B) IRE1 mRNA levels in EZH2 wild-type (wt) and EZH2-mutated (mt) GCB DLBCL patients. Data extracted from gene expression data sets GSE23501. Wilcoxon signed-rank test, *P ≤ .05. (C) ChIP was performed on ABC and GCB DLBCL cell lines using H3K27me3-specific antibody. Enrichments of indicated promoters were probed by real-time PCR (mean and SD of technical triplicates of 1 representative experiment of 3). MyoD and Hoxa7 regions are positive controls for H3K27me3-mediated repression. GAPDH and BCL6 promoters are negative controls for H3K27me3-mediated repression.