The NBSGW strain demonstrates enhanced human LT-HSC engraftment in the BM. (A) Schematic of generating humanized mouse models using UCB-derived human HSPCs in NSG and NBSGW strains. (B) Survival of mice over 150 days after humanization. Day 0 (NSG: n = 23; NBSGW: n = 25), day 150 (NSG: n = 12; NBSGW: n = 24). (C) Weights of mice. Error bars indicate standard deviation (SD). (D) Percent human CD45⁺ cells in the PB of mice. The curve represents the mean values of each time point. Week 8 (NSG: n = 15; NBSGW: n = 24). Week 18 (NSG: n = 12; NBSGW: n = 24). (E) Percent human CD45⁺ cells in the murine BM. (F) Percent human CD34⁺ cells of human CD45⁺ cells. (G) Percent human CD34⁺CD38^low cells of human CD45⁺ cells. (H) Percent human CD34⁺CD90⁺ cells of human CD45⁺ cells. (NSG: n = 12; NBSGW: n = 24). Error bars indicate SD. Welch t test, ∗∗P < .01, ∗∗∗P < .001, and ∗∗∗∗P < .0001. (I) Representative plots showing the gating strategy used to characterize human cells isolated from murine BM.