Genetically determined blood LTL has previously been associated with GBM risk, based on a 5% subset of the GWAS data we analysed.19 The association is principally driven by the TERT, TERC and OBFC1 SNPs, whereas the RTEL1, NAF1, ACYP2 and ZNF208 SNPs show only limited support for an association (Supplementary Table A-C2, Supplementary Figs. 2–4). This evidence concerns the gene RTEL1 and glioblastoma.