IDH2 and glioma: Recent studies have correlated the absence of TP53 with chromosome segregation errors and chromosomal instability [25, 26], suggesting that TP53 mutations occur during the early phase of tumorigenesis in IDH mutant gliomas and cause chromosomal instability and gene dysregulation in specific regions such as 7q, 8q, 9p, 11p, or 12p.