The extensive changes in gene expression seen in MLL-driven AML cells in response to MYB depletion include the modulation of many genes that are known to be targets of MYB, including PIM1, ITGAM, GFI1, FLT3, CD14, CCND2, S100A9 and DUSP6. Most interestingly, MYB depletion is accompanied by a striking increase in the abundance of MAFB RNA. This evidence concerns the gene S100A9 and acute myeloid leukemia.