Asxl1 truncation promotes the expansion of myeloid-biased stem cells. (A) Representative hematoxylin and eosin (H&E)–stained tibia cross-sections of mice 1 year post-Cre induction (n = 3 per group). (B) Schematic of serial transplant of all 4 genotypes and timeline of bone marrow characterization by flow cytometry. (C) Flow cytometry analysis of the long-term hematopoietic stem, LT-HSC CD41⁺/CD41⁻ ratio, and GMP progenitor cells from mice bone marrow at 4 months, 1 year after Cre induction and after both serial transplants (n = 3-4 per group). (D) Quantification of colony-forming unit assays at 1 year post-Cre induction and after both serial transplants using 1 × 10⁴ cells per well of whole bone marrow cells (mean ± standard error of the mean [SEM]; n = 3 per group in triplicate). Significance was evaluated with a 2-way analysis of variance (ANOVA) with Tukey multiple comparison test. ∗P < .05, ∗∗P < .01, ∗∗∗P < .001, ∗∗∗∗P < .0001.