Moreover, when IER5 over-expressed, the significantly reduced binding of NF-YB on the Cdc25B promoter the release of anti-histone acetyltransferase p300, which is known as a coactivator of NF-Y [15], was observed at upstream of 1st exon of Cdc25B. On the other hand, we did not observe that IER5 interacts with Sp1 in AML cells. This evidence concerns the gene SP1 and acute myeloid leukemia.