IDH1 and central nervous system cancer: In glioma, advances in magnetic resonance spectroscopy (MRS) allowed researchers to effectively measure 2HG in vivo with good correlation with IDH mutation status [107,108,109,110,111,112], whereas MRS can measure total 2HG at the tissue level, chromatography coupled with mass spectrometry enables the specific quantification of R- and S-stereoisomers in the cerebrospinal fluid, serum and urine.