The irregular expansion and dysfunction of pre-disease Wt1 mutant hematopoietic MEP progenitor cells in our model, coupled with the eventual development of erythroid dysplasia and anemia in the Wt1 mutant mouse model, indicate that a mutation in Wt1 leads to a disease phenotype by interfering with normal erythropoiesis. This evidence concerns the gene WT1 and anemia (phenotype).