IDH2 and glioma: Third, IDH1 mutations can be identified by routine IHC.796 Fourth, techniques for the noninvasive detection of 2-hydroxyglutarate (2-HG) accumulation in glioma patients have been developed.797 Moreover, given that D2HG is upregulated in tumors with IDH mutations, elevated D2HG level in tumor tissues is used as a noninvasive detection biomarker for clinical IDH mutated tumors.793 In conclusion, IDH1/2 mutations are meaningful diagnostic biomarkers of tumor metabolism.