Activation of the NFκB system is important for transcriptional regulation, and inhibition of NFκB delays mitotic entry and inhibits transcription of G2/M-specific genes, including cyclin B, PLK1, and CDC25B [95]. NFκB is important for AML stem cell functions and their chemosensitivity [96], but it is not known whether its effect on leukemic stem cells is mediated through altered CDC25B expression. This evidence concerns the gene PLK1 and acute myeloid leukemia.