Notably, glioblastomas have the wild type, nonmutated IDH (isocitrate dehydrogenase) gene, while astrocytomas are IDH-mutant, and oligodendrogliomas are IDH-mutant and also have the 1p/19q codeletion (see Table 1) [5]. The gene discussed is IDH1; the disease is astrocytoma (excluding glioblastoma).