Human immune system reconstitution in spleen, liver, and bone marrow of HIS versus HIS-SGM3 mice. Twelve weeks after human CD34⁺ HSC engraftment, various organs from HIS and HIS-SGM3 mice were analyzed for human immune cell subset reconstitution by flow cytometry. Frequencies of human CD3⁺ T cells (A), CD19⁺ B cells (B), and CD33⁺ myeloid cells (C) in spleen, liver, and bone marrow of HIS (◇) and HIS-SGM3 (♦) mice are shown. (D) Total cell counts of indicated human immune cell subsets in the liver, spleen, and bone marrow. (E) Representative fluorescence-activated cell sorter dot plots for bone marrow and spleen. Unpaired Student t test: *P ≤ .05; **P ≤ .005; ***P ≤ .0001. BM indicates bone marrow; error bars indicate SEM.