IDH1 and central nervous system cancer: Thus, among grade II or III gliomas, approximately 30% of tumors display the three alterations together, 5% had IDH and TERT mutations, 45% had only IDH mutations, 7% were triple negative, and 10% had only TERT mutations; the triple and double-positive gliomas have better prognosis; the IDH-only mutated and the triple-negative gliomas have an intermediate prognosis, while the TERT only-mutated gliomas have a poor prognosis, comparable to glioblastomas [156] (Figure 6).