IDH2 and central nervous system cancer: For lower-grade glioma cases (n = 392), 103 (26.3%) were triple-positive, 19 (4.8%) had both IDH and TERT mutations, 100 (25.5%) had IDH mutation only, 48 (12.24%) had TERT mutation only, 78 (19.9%) were triple-negative, and 44 (11.2%) had other combinations (Figure 1B).