IDH1 and central nervous system cancer: We previously demonstrated the efficacy of mIDH1 inhibitors at decreased production of 2HG in both mouse and human mIDH1 glioma cells.15,18 We then proceeded to evaluate the differential enrichment at promoter regions of H3K4me3, a transcriptional activation mark, and of H3K27me3, a transcriptional repressive mark in mIDH1 compared to WT-IDH1 NS (Figs. 2b–c).