On the other hand, an almost two-fold difference of rs55705857-associated risk between IDH-mutated WHO grade-II and grade-III tumors (ORs 11.51 vs. 6.11; p < 0.0001 vs. p = 0.0003, respectively) suggests a strong grade-specific bias of rs55705857-glioma association (Fig. 2a and Supplementary Table 2). Here, IDH2 is linked to central nervous system cancer.