Mixed (normal and leukemic) engraftment of CD34⁺ cells from NPM1-mutated AML-immunodeficient mice. (A-F) Bone marrow paraffin sections from a vertebral body of an NOG mouse, inoculated (18 weeks before) with 1 × 10⁶ CD34⁺ cells (purity 79%) from patient 30 (Table 2). An area in the bottom part of panel A (square) is packed with leukemic cells expressing hCD45 (B left square), cytoplasmic NPM1 (C) and nucleus-restricted C23 (D). Another area from the same section shows involvement by normal human hemopoietic cells (square in the top part of panel A), expressing CD45 (B right square), nucleus-restricted NPM1 and C23 (E-F single and double arrows). (A) Hematoxylin-eosin. (B-F) APAAP, hematoxylin counterstaining. Images were collected using an Olympus B61 microscope and a UPlanApo 20×/0.70 (A-B), UPlanApo 40×/0.85 (C-F); Olympus E330-ADU1.2× camera; and Adobe Photoshop 7.0.