Effect of GBP2 OE on hematopoiesis in vivo. (A) Western blot analysis of mouse Gbp2 protein expression in Mx1-Cre and Mx1-Cre Ezh2^Y641F CD19⁺ B-cell progenitors from the BM. (B) Experimental design of in vivo GBP2 OE. (C) GBP2 expression levels by qPCR in ckit⁺ hematopoietic progenitors 24 hours after transfection (n = 3). (D) Level of GBP2-GFP⁺ cells in peripheral blood cells of transplant recipient mice over 5 months (EV ctrl, n = 5; GBP2 OE, n = 6; ∗∗P < .01 as indicated). (E) Representative flow cytometry plots of GFP expression at the 3-month time point from panel D. (F) Level of apoptosis measured by flow cytometry for annexin V and 7-AAD at different time points after transplantation (n = 5-6). (G) Representative flow cytometry plots for analysis of panel F at the 5-month time point. (H) Lineage distribution within the GFP⁺ fraction of Mx1-Cre Ezh2^Y641F transduced cells (n = 8-9). (I) Representative flow cytometry plots of panel H. (J) Lineage analysis by flow cytometry of peripheral blood from transplant recipients (EμMyc donor group; n = 9). (K) WBC counts and expansion of B cells in mice from panel J. For panels A-K, a multiple parameter unpaired t test was performed. 7-AAD, 7-Aminoactinomycin D; EV ctrl, empty vector control; Gapdh, Glyceraldehyde-3-phosphate Dehydrogenase; OE, overexpression; WBC, white blood cells.