AML is observed in animals transplanted with βc^−/− RUNX1-ETO cells. (A) Cytological analysis of a representative leukemic βc^−/− MigRE animal. Peripheral blood (PB) smears, BM, and spleen (SP) cytospin samples stained with Wright-Giemsa are shown (original magnification, 400×). (B) Histopathological analysis of a representative leukemic βc^−/− MigRE animal. H&E-stained sections of the BM (original magnification, 200×) and SP (original magnification, 100×) are shown. (C) Splenomegaly observed in leukemic βc^−/− MigRE animal. (D) Flow cytometric analysis of the BM from a representative leukemic βc^−/− MigRE animal; numbers represent percentage in GFP⁺BM cells. CD3/B220 are lymphocyte markers; CD11b/Gr-1, granulocyte markers; Ter119/CD71, erythroid markers. (E) Flow cytometric analysis of myeloid progenitor (MP) or LSK from a representative leukemic βc^−/− MigRE animal. Respective percentages in GFP⁺BM are shown. (F) Flow cytometric analysis of MP populations from a representative leukemic βc^−/− MigRE animal. CMP indicates common myeloid progenitor; GMP, granulocyte-macrophage progenitor; and MEP, megakaryocyte-erythrocyte progenitor.