Hypoallelic mice have a mixed MDS/MPN disease. Peripheral blood smear (A), BM cytospin (B), and spleen cytospin (C) showing increased myeloid cells (animal #3339 used for images). Scale bars represent 50 μm (100×/1.30 NA oil objective magnification). (D) Dysplastic cells observed in peripheral blood, BM, and spleen of hypoallelic mice include hypersegmented granulocytes (i, ii, v, ix, and x), pseudo-Pelger-Huet-like atypical white cells (vi and xi), Howell-Jolly bodies (iii, indicated by arrow), dysplastic megakaryocytes (vii), and increased immature white cells (iv, vii, viii, and xii). Both NR4A1^−/−NR4A3^+/− (n = 2, at 9-11 months) and NR4A1^+/−NR4A3^−/− (n = 4, at 4-7 months) mice were used for this assay.