Extramedullary hematopoiesis in Mx1-Cre Ezh2Y641F mice. (A) Spleen weight comparison in Mx1-Cre Ezh2Y641F vs Mx1-Cre–only control mice (n = 5 per group). (B) Representative images of spleen size (top) and cells in Hanks Balanced Salt Solution (HBSS) suspension (bottom). (C) H&E-stained spleen sections showing extramedullary hematopoiesis in Mx1-Cre Ezh2Y641F and Mx1-Cre control mice. (D) Flow cytometry of blood lineage markers (B220, CD4, CD8, Mac1, and Ter119) in spleen cells from Mx1-Cre Ezh2Y641F and Mx1-Cre mice (n = 4-6). (E) Flow cytometry analysis of hematopoietic progenitor populations in spleens from Mx1-Cre Ezh2Y641F and Mx1-Cre control mice; representative of 3 independent experiments. Error bars represent standard deviation. ∗P < .01; ∗∗ P <.001.