IDH2 and central nervous system cancer: Markers such as IDH1 R132, IDH2 R172, H3F3A K27 and G34, and HIST1H3B K27 are associated with distinct methylation-based tumor classes [1], while BRAF V600E and pTERT C228T/C250T have been observed in various types of glioma [16] and other types of cancer [23].