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. The gene discussed is CDC25B; the disease is acute myeloid leukemia.