IDH2 and central nervous system cancer: Finally, it is worth noting that we focused our study on pathways related to adult primary GBM and not on pathways involved in (1) low-grade glioma or secondary high-grade glioma, such as mutations on isocitrate dehydrogenase 1 (IDH1) and IDH2 [75] and loss of alpha thalassemia/mental retardation syndrome X-linked (ATRX) [76]; or (2) pediatric glioma, such as mutations on B-Raf V600E mutation [77] and H3.1/H3.3 K27M mutation.