a, Lethality b, anemia c, decreased erythroid progenitors and increased percentage of d, monocytic/granulocytic, e, LSK, f, myeloid progenitor populations in the marrow and g, immature monocytic blasts and h, hypersegmented neutrophils in the blood (13-81% neutrophils and 12%-90% blasts). i, Bone marrow sections showing micro-megakaryocytes with hyperchromatic nuclei and j, blasts. k, In the spleen, cells with large nucleoli (dotted arrow) and dysplastic megakaryocytes (white arrow). l, Cluster of immature cells with atypical nuclear appearance in the liver. m, Increased percentage of undifferentiated imature myeloid cells in the bone marrow of βCat(ex3)osb mice. n, Lack of myeloid cell differentiation in βCat(ex3)osb bone marrow cells. N=8 mice per WT and 12 mice per βcat(ex3)osb groups. Results show a representative of five independent experiments, *p < 0.05 versus WT. Results are mean ± SD. MNC: mononuclear cells.