Histopathology of mice receiving transplants of Pim2–PML-RARα or empty vector–PML-RARα HPCs. Histologic sections from liver, lung (A), and spleen (B) were stained with hematoxylin and eosin (×40 magnification for A and B; ×10 and ×100 magnification for B). Note the myeloid infiltrate in the organs of Pim2-PRα mice.