IDH1 and central nervous system cancer: We found that HOTAIR and HOXA9 frequently have a coherent transcriptional activation status in grade IV glioma (Portuguese dataset Pearson’s r = 0.642, p < 0.0001; IDH-wt GBM in French dataset Pearson’s r = 0.649, p = 0.002; IDH-wt GBM in TCGA microarray dataset Pearson’s r = 0.494, p < 0.0001; IDH-wt GBM in TCGA RNA-seq dataset Pearson’s r = 0.525, p < 0.0001; Figure 3A–3C, Supplementary Figure 2H and Table 1).