IDH1 and central nervous system cancer: According to the World Health Organization, glioblastomas are grouped into three categories based on isocitrase dehydrogenase (IDH) status: glioblastoma IDH-wildtype, which is designated as primary or to have originated de novo; glioblastoma IDH-mutant, which is identified as a secondary tumour, arising from a lower grade glioma; and glioblastoma not otherwise specified (NOS) for tumours when IDH evaluation cannot be performed [6].