IDH1 and glioblastoma: Given the widely known clinical relevance of isocitrate dehydrogenase [NADP (+)] 1 (IDH1) mutation, O-6-methylguanine-DNA methyltransferase (MGMT) methylation and cytosine-phosphate-guanine (CpG) island methylator phenotype (CIMP) status in GBM [2], we also explored the distribution of ISs in different IDH1 mutation, MGMT methylation and CIMP states.