Cytotoxicity was assayed by MTT. Induction of apoptosis and differentiation of AML stem and progenitor cells were observed. Cytotoxicity was attributed to apoptosis by the suppression of NF-kB and its downstream proteins. p65, XIAP, FLIP, Bcl-2, Bax, and the cleavage of PARP, caspase-3, and caspase-9 were detected by Western blots in primary CD34+ cells, HL60, and KG1a cells. This evidence concerns the gene CASP9 and acute myeloid leukemia.