An independent AML cohort confirmed the positive effect of high BRE expression on prognosis. (A) BRE expression was high in a subset of a second cohort of 436 AML patients and co-occurred highly with MLL-AF9 translocations (P < .001 based on Fisher exact tests). cDNA (40k) expression array data of BRE (clone: IMAGE:739993) were log transformed and mean centered. Patients were subdivided into 3 groups based on MLL-AF9 and 11q23 positivity. Dotted lines represent the mean of all AML samples plus 3 or 4× the SD of BRE expression, used as values for outlier analysis and cutoff for high BRE expression, assigning 7 or 3 samples with high expression, respectively. (B) High BRE expression accounts for good OS within an independent MLL-AF9 cohort (5-year OS of 7.1 ± 6.9 vs 63.6 ± 14.5%, P = .0089 for patients with normal and high BRE expression, respectively). BRE array expression data of 2 cohorts of MLL-AF9–positive patients were combined by log transformation and mean centering of the data. Based on the cutoff used for high BRE expression in panel A (mean of 436 AML samples + 3 × SD), MLL-AF9 patients were subdivided into 2 groups: high and normal BRE expression (see supplemental Table 2). P values were determined with the log-rank test. The number of patients included in the analyses is shown in brackets.