In short, numerous targeted and large-scale studies have now demonstrated that molecular features are superior to histologic criteria in terms of diagnosis and prognosis of lower-grade IDH-mutant astrocytomas [4,36,41,43,46,52,66,73,74], however, unified and integrated terminology for combining the known genetic and epigenetic factors remains to be devised. This evidence concerns the gene IDH2 and astrocytoma (excluding glioblastoma).