CD71^lo (ie, MYC^lo) HSCs exhibit enhanced long-term repopulation. Human CD45 engraftment (A), lineage potential (B), and percentage of human CD34⁺ primitive subsets (C) were assessed at 16 weeks after transplantation for each NSG mouse transplanted with the indicated fresh unexpanded HSCs subset. Human CD45 engraftment (D), lineage potential (E), and percentage of human CD34⁺ primitive subsets (F) were assessed at 16 weeks after transplantation for each NSG mouse transplanted with UM171-expanded CD71 subsets. Two-sided Mann-Whitney U test; ∗P < .05, ∗∗P < .01, and ∗∗∗P < .001. ns, not significant.