E47 null HSCs show normal homing, niche engraftment, and apoptosis. (A) CD45.2 WT or E47 KO bone marrow cells (2 × 10⁶) were injected into lethally irradiated CD45.1 recipient mice. The number of donor-derived flk2⁻ LSKs was examined at 2 weeks (n = 3 mice) and at 16 weeks (n = 8 mice) after transplantation. (B) Lethally irradiated CD45.1 recipient mice reconstituted with E47 KO or WT CD45.2 donor bone marrow cells were killed at 12 weeks after transplantation. The bone marrow cells from these recipients were stained with antibodies to resolve donor-derived CD45.2 flk2⁻ LSKs and then labeled with annexin V and DAPI for apoptosis analysis. (Left panels) Representative flow cytometry profiles used to generate the bar graph on the right (n = 3 mice). **P < .05. ns indicates not significant.