Heatmaps visualizing the expression levels of the 86 probe sets used in the prognostic gene signature. The heatmaps show the relative levels of expression for the 86 probe sets in 163 patients in the training cohort (A), 79 patients in the test cohort (B), and in the 64 patients in the validation cohort (C). The probe sets are arranged according to their univariate Cox score for correlation with overall survival, with those having the highest negative score shown on top and those with the highest positive score shown at the bottom. Green spots indicate below-average expression; red spots, above-average expression. Below each heatmap, the continuous score calculated from these 86 expression values is visualized. NPM1 and FLT3 status are color-coded: A yellow mark indicates the presence of an NPM1 mutation or FLT3 ITD; blue mark, the absence of the mutation. In panel A, the 2 patient groups generated by 2-means clustering of the continuous score values are depicted in green and red. The mean of the 2 cluster centers was subsequently used as a cutoff threshold in the test and validation cohorts to allow dichotomization of the continuous risk score, as indicated in green and red in panels B and C.