Engraftment of MM HSPCs is enhanced in xenotransplantation assays. A total of 1-3 × 10⁶ HSPCs obtained from the BM of 4 healthy donors and 4 MM patients were transplanted into sublethally irradiated NOG mice by intrafemoral injection. Peripheral blood (PB) was analyzed 4 weeks after transplantation and analyzed by flow cytometry. (A) Mean proportions of human CD45⁺ hematopoietic cells within PB. (Bi-iii) Mean proportions of CD19⁺, CD33⁺, and CD71⁺ cells are shown. (C) Total BM (TBM) cells were harvested 30 weeks after transplantation and analyzed by flow cytometry. Representative FACS plots show the proportions of human CD45⁺ hematopoietic cells within TBM after transplantation of HSPCs obtained from the BM of a healthy donors and a MM patient, respectively. (D) Bar chart shows the mean proportions of the human CD45⁺ cell population within TBM cells for all experiments. Human hematopoietic differentiation markers were analyzed in human CD45⁺ cells 30 weeks after transplantation. (Ei-iv) Bar charts show mean proportions of CD19⁺, CD11b, CD33⁺, and CD71⁺ cells. Error bars represent SD. Paired 2-tailed t test was used to detect statistically significant differences. *P < .05; ***P < .001.