IDH2 and glioblastoma: Considering the gliomagenesis and aggressiveness of glioma, Louis et al. (2016a) these findings are of high therapeutic impact: while IDH mutation is a key pathway in gliomagenesis of WHO grade II and III gliomas and secondarily progressed WHO grade IV glioblastomas, IDH wild-type is a typical hallmark of primary WHO grade IV glioblastomas.