FLT3 and myeloproliferative neoplasm: In striking contrast, Flt3+/ITD/Wt1+/R394W mice exhibit dysplastic changes in the erythroid lineage with irregular nuclear borders and multinucleate erythroid precursors reminiscent of the Wt1+/R394W mice (Figure 4C), though with myeloid proliferation reflective of the ITD-induced MPN.