CDKN1A and acute myeloid leukemia: In addition, within the top 10 genes up-regulated in AML-M5, we also found CDKN1A, which encodes a cyclin-dependent kinase inhibitor that promotes maintenance of leukemia stem cells [44], and the ZEB2 transcription factor, a master regulator of epithelial to mesenchymal transition [45] that also has been implicated in cancer and leukemia stem cell maintenance [46–48].