Expression of MLL and HOXA genes. Quantitative reverse transcription–polymerase chain reaction analyses from RNA samples of various acute myeloid leukemia samples with the indicated oncogenic events. Expression was normalized with respect to ABL expression. Note the logarithmic nature of the scales. Patients bore the indicated genetic abnormality. NUP indicates NUP98 fusion gene (see Romana et al9 for details); MLL, MLL-AF10 fusion gene; ITD-MLL, internal tandem duplication; amplification, amplification of the MLL locus; and RUNX1-ETO, runt-related transcription factor 1–821 gene. Because the MLL assay maps at the 3′ end of the transcript, only expression of the untranslocated copy of MLL was detected in samples with MLL fusion.