It is not clear yet if GFI1B could play some role in rare myeloid cells, but high expression of functional GFI1B not only in erythroid/megakaryocytic lineage but also in non-erythroid/megakaryocytic myeloid cells has been associated with both chronic and acute myeloid leukemias, suggesting that it can act as a proto-oncogene possibly by supporting cell survival in cells where it is not normally expressed (Elmaagacli et al., 2007; Vassen et al., 2009). This evidence concerns the gene GFI1B and acute myeloid leukemia.