Partial block in B-cell development in Mx1-Cre Ezh2^Y641F mice. (A) Complete peripheral blood cell counts (CBCs) showing WBCs, NEs, LYs, RBCs, and platelets in peripheral blood from Mx1-Cre Ezh2^Y641F and Mx1-Cre control mice (n > 5 per group). (B) Platelet counts from CBC analysis. (C) Flow cytometry analysis of peripheral blood in Mx1-Cre Ezh2^Y641F and Mx1-Cre–only control mice (n > 5). (D) Calculated absolute numbers of B cells, T cells, and myeloid cells in the peripheral of Mx1-Cre Ezh2^Y641F and Mx1-Cre control from flow cytometry in panel A and CBC in panel C. (E) Representative flow plots of data in panel C. (F) Representative flow cytometry of bone marrow B-cell progenitor populations in Mx1-Cre Ezh2^Y641F and Mx1-Cre–only control mice; black box indicates pre–pro-B cells. (G) Quantification of bone marrow B-cell populations in Mx1-Cre Ezh2^Y641F and Mx1-Cre control mice (n > 5). Error bars indicate standard deviation. ∗P < .01; ∗∗P < .001. LY, lymphocyte; NE, neutrophil; RBC, red blood cell; WBC, white blood cell.