They are frequently associated with IDH-wildtype gliomas in combination with gain of chromosome 7 and loss of chromosome 10 (+7/−10) or EGFR amplification; exclusion of +7/−10 or EGFR amplification events do not preclude aggressive clinical behaviour in some cases with TERTp mutations [16,17,18,19]. The gene discussed is IDH2; the disease is central nervous system cancer.