Consistent with the idea that IER5 and TMPP effects were mediated by a decrease in Cdc25B, we found that over-expression of Cdc25B rescued both the inhibitory effects of TMPP treatment and those of IER5 over-expression in ALDHhi/CD34+ AML progenitor cells, resulting in recovery of the colony forming activity of AML-derived ALDHhi/CD34+ cells. The gene discussed is CD34; the disease is acute myeloid leukemia.