HMGA2 does not modulate the effect of RUNX1 deficiency on HSPC expansion. Percentages of hematopoietic stem cell populations analyzed by flow cytometry, including (A) LSK cells, (B) LT-HSCs, and (C) ST-HSCs. For LSK: wild-type (Hmga2^+/+ or Hmga2^+/−, Runx1^(fl/fl), Mx1Cre^–, n = 15), Hmga2^−/− (Hmga2^−/−, Runx1^(fl/fl), Mx1Cre^–, n = 9), Runx1^Δ/Δ (Hmga2^+/+ or Hmga2^+/−, Runx1^(fl/fl), Mx1Cre⁺, n = 21), Double KO (Hmga2^−/−, Runx1^(fl/fl), Mx1Cre⁺, n = 8). For LT-HSCs and ST-HSCs: wild-type (n = 10), Hmga2^−/− (n = 4), Runx1^Δ/Δ (n = 10), Double KO (n = 4). (D) Representative flow cytometry gating of LSK and SLAM populations for each of the 4 genotypes of mice and their averages are shown. (E) Percentages of CLP populations were analyzed by flow cytometry. For CLPs: wild-type (n = 5), Hmga2^−/− (n = 5), Runx1^Δ/Δ (n = 10), Double KO (n = 4). (F) Averages of frequencies of Annexin V–positive/7AAD-negative cells from the LSK cells of each genotype (n = 4 each) are shown. *P < .05.