IDH1 and glioma: Furthermore, several RNAs have been recognized as glioma-specific biomarkers including EGFR (EGFRvIII, epidermal growth factor receptor variant III), isocitrate dehydrogenase 1 (IDH1), a promising therapeutic target in selected cancers with a mutated version of the mitochondrial enzyme IDH1, and miR-21 [86,122].