Flow cytometric analysis of (A) BM, (B) spleen, and (C) PB of an animal transplanted with 25 × 10⁶G-CSF–mobilized human peripheral blood CD34⁺ cells. The percentage of human cells (CD45⁺ and mCD18⁻) is indicated in the graphs. The spleen of this animal was enlarged as compared with control (17 × 10⁶v 5.4 × 10⁶ cells). In (D), humerus of this animal (top) as compared with the humerus of an irradiated nontransplanted control animal (bottom). In (E) and (F), histology (hematoxylin and eosin stain) of the bone marrow of control and transplanted animal, respectively.