Expression of MLL and HOXA9 in unselected patient samples. Geometric average of the MLL (□) and HOXA9 (▦) expression in normal marrow (n = 14), MDS (n = 11), and AML (n = 11) samples, with normal 11q23 copy number in the absence of an MLL gene rearrangement. P values indicate the significance of the difference in observed expression in 2-by-2 analyses of the different patient groups, as identified by the Mann-Whitney test.