Human iPSC-derived bone marrow organoid supports autonomous hematopoiesis. (A-E) Validation of multilineage hematopoiesis within the organoid through flow cytometry. After digestion with collagenase into a single-cell suspension, organoid-derived cells were stained as indicated. Labels in the bracket symbols indicate the cell populations the corresponding panels were based on for analyses. The percentages of the indicated populations are presented. (F) Organoid implantation in NSG mice. The organoid was implanted under the renal capsule of the left kidney. H&E staining demonstrates successful engraftment 1-month after implantation. Red arrows indicate the vessel lumen enclosing red blood cells (RBCs). (G) Flow cytometry analysis of RBC-depleted peripheral blood at 1, 5, and 11 months after implantation to compare the percentages of human and mouse CD45⁺ leukocytes. CD235a⁺ human erythroid cells were also tested at 5 months using non–RBC-depleted samples. (H) Quantitative analysis of the ratio of human and mouse CD45⁺ cells in panel G. Each data point represents an NSG mouse implanted with human bone marrow organoid. SSC, side scatter.