IDH1 and glioblastoma: Thereby, we found that chromosome 10 deletion and TERT promoter mutation are both clonal in most IDH-wildtype glioblastomas, which is in line with previous whole genome sequencing data showing TERT promoter mutations as clonal events in the majority of these tumors, while subclonal TERT promoter mutations were found in a subset of IDH-wildtype glioblastomas [58].