The additional features identified in TCGA (CIC, ATRX, PIK3R1, IDH2, GRIN2A, NOTCH1, TP53, EGFR, MUC16) and CGGA (PDGFRA) provide interesting avenues for analysis of progression to a higher grade in glioma via linkage to known signaling pathways of tumor progression and treatment resistance (Table 1, Figure 4). This evidence concerns the gene IDH2 and central nervous system cancer.