Immunophenotypic and morphologic characterization of Pim2-PRα–induced leukemias. Costaining of CD34 and Gr1 on BM cells and cytospin morphology from mice that received a transplant of empty vector–transduced PRα bone marrow (A-B), diseased knock-in PRα mice (C-D; that did not undergo transplantation), and mice that received a transplant of Pim2-transduced PRα bone marrow after developing leukemia (E-F) is shown. For analysis of CD34 and Gr1, live cells (4,6 diamidino-2-phenylindole negative) were gated for CD45.2⁺ (donor cells), and subsequent percentages of cells positive for CD34 and or Gr1 were calculated. Cytospin preparations of BM cells were stained with Wright-Giemsa (original magnification ×60).