Studies of RUNX-1ⁱⁿ adult CD34⁺ HSPCs. NT- or RUNX1-targeting shRNA lentiviral-transduced (supplemental Figure 2) CD34⁺ HSCs. (A) Quantitation of RUNX1 mRNA levels in day 14 Mk cultures by quantitative PCR with RUNX1 levels in NT control shRNA-treated cells set as 1 (n = 3-5 experiments per study arm). (B) Day 14 Mk yield ±1 SEM from RUNX1 shRNA-transduced CD34⁺ HSPC cultures as a percentage of the NT control shRNA (n = 3-5 experiments per study arm). (C) Colony-forming assays performed in sorted NT- and RUNX1 shRNA-expressing CD41⁻ and CD41⁺ HPSCs. Sorted cells were seeded in MegaCult medium for Mk colonies or MethoCult medium for erythroid and GM colonies (n = 4 experiments per study arm). (D) Quantitation of the number (mean ± 1 SEM) of terminal day 14 Mks from sorted CD41⁻ and CD41⁺ HPSCs as a percentage of the NT control (n = 4 experiments per study arm). (E) Quantitation of the percentage of annexin V⁺ cells from sorted CD41⁻ and CD41⁺ HSPCs in NT and RUNX1 shRNA lentiviral-transduced cells. Mean ±1 SEM (n = 3 experiments per study arm). All data are expressed as the mean ±1 SEM, with P values by Student t test.