Effect of Ezh2^Y641F expression timing on gene expression programs in pro- and pre–pro-B cells. (A) Experimental schematic: RNA sequencing was performed on pre–pro- and pro-B cells sorted from bone marrow of Ezh2^WT and Ezh2^Y641F from Mx1-Cre and CD19-Cre models. (B) Volcano plots of Differentially expressed genes (DEGs) in Ezh2^Y641F vs Ezh2^WT CD19-Cre pro-B (left), Ezh2^Y641F vs Ezh2^WT Mx1-Cre pro-B (center), and Ezh2^Y641F vs Ezh2^WT Mx1-Cre B pre–pro-B cells (right). (C-D). Gene set enrichment analysis of hallmark signatures in CD19-Cre (circles) and Mx1-Cre (triangles) Ezh2^Y641F pro- (C) and pre–pro-B cells (D). (E) Heat map of GTPase activity genes, enriched in Mx1-Cre Ezh2^Y641F pro-B cells compared to Mx1-Cre Ezh2^WT control. (F) Enrichment plot for GO GTPase activity signature. (G) Volcano plot highlighting upregulated GBP genes in Mx1-Cre Ezh2^Y641F vs Mx1-Cre Ezh2^WT control pro-B cells. (H) GTPase-related GO terms in enriched in Mx1-Cre Ezh2^Y641F vs Mx1-Cre Ezh2^WT control pro-B cells. (I) GBP expression fold change after EZH2 inhibition with GSK343 in human lymphoma cell lines (data from GSE45982^8,14). (J) H3K27me3 ChIP-seq tracks in Ezh2^WT or Ezh2^Y641F mouse centroblasts and centrocytes at Gbp loci on Chrs 5 and 10 (data from GSE138036²⁶). Chr, chromosome; GO, gene ontology; MPP, multipotent progenitors; NS, not significant; Ref, reference genome.