For all of the following glioma biomarkers the evidence level was regarded as lower than of 1p/19q status (IIB) by the task force based on currently available data: isocitrate dehydrogenase (IDH) mutation testing (diffusely growing gliomas) [11, 12], MGMT gene promoter methylation testing (glioblastoma) [13], v-RAF murine sarcoma viral oncogene homolog B1 (BRAF) fusion testing (pilocytic astrocytoma) [14] and CpG island methylator phenotype (CIMP) testing (diffusely growing gliomas) [15]. The gene discussed is IDH3A; the disease is glioma.