IDH1 and central nervous system cancer: Of the 32 patients that were diagnosed with diffuse glioma, i.e., astrocytoma, anaplastic astrocytoma, glioblastoma, or high-grade glioma (HGG), histone alterations were found in a little over a third (nine cases of H3K27M, one case with EGFR ex 20 mutations, and one case of H3 G34R mutation), and IDH1 mutations in six (four with IDH1 R132H and two with IDH1 R132S mutations (Table 1, Figure 1).