NAF1 and central nervous system cancer: To determine whether the association of glioma risk with genotypically-estimated LTL was due only to the previously established associations of glioma risk with SNPs near TERC, TERT and RTEL1, LTL estimates were re-calculated in the combined discovery and replication dataset using the other five LTL-associated SNPs located near genes that had not been previously associated with glioma risk (ACYP2, NAF1, OBFC1, CTC1 and ZNF208).