IDH1 and neoplasm: Indeed, when the same gene set was used to produce k-means clusters in the validation set, one cluster showed uniformly elevated expression of the glycolytic gene set and was significantly enriched for IDH-wt patient tumor samples (50% of glycolytic-high cluster samples vs 4% of glycolytic-low cluster samples; P < .0001, x2 = 76.76; Figure 2A).