IDH1 mutations in GBM were first reported by Parsons et al. in 2008, [28] who pointed out that “mutations in IDH1 occurred in a large fraction of young patients and in most patients with secondary glioblastomas and were associated with an increase in OS.” Although IDH mutations can be found in up to 80% of grade II–III gliomas and secondary GBMs, they are rare in primary GBMs [6, 29–31]. Here, IDH1 is linked to glioblastoma.