The rs3851634 maps to intron 12 of the gene encoding polymerase III, RNA, subunit b (POLR3B; Fig. 2a) within a ∼350-kb block of linkage disequilibrium (LD) at 12q23.3, which also contains the genes CKAP4 and TCP1L2. The other four SNP associations defined by rs11196067, rs648044, rs12230172 and rs1801591 were specific to non-GBM glioma. Here, POLR3B is linked to glioblastoma.