Increased apoptosis in Gata2 +9.5^+/− and Gata2^+/− HSPCs. Six-week-old WT C57BL/6 (Control), Gata2 +9.5^+/− (+9.5^+/−), and Gata2^+/− (Gata2^+/−) mice were analyzed. (A) Gating strategy for HSCs and MPPs. HSCs and MPPs are defined based on LSK SLAM markers as described in Methods. Their frequencies were quantified in BM and SP. (B,D) Quantification of apoptotic BM HSCs (B) and MPPs (D) using Annexin V and 4′,6-diamidino-2-phenylindole (DAPI). (C,E) Cell cycle profiling of BM HSCs (C) and MPPs (E) using Ki67 and DAPI. The results are presented as mean ± standard deviation (SD). *P < .05; **P < .01; ***P < .001.