IDH1 and central nervous system cancer: Furthermore, in IDH-wt (n = 55) and IDH-mut (n = 137) grades II and III glioma with available RNA-seq data from TCGA, a statistically significant correlation between the expression of HOTAIR and HOXA9 was also found (IDH-wt Spearman’s r = 0.65, p < 0.0001, and IDH-mut r = 0.21, p = 0.01; data not shown), while in 1p19q codeleted and IDH-mut grades II and III glioma no correlation was found (n = 85, r < 0.01, p = 0.999; data not shown).