Similarly, two further glioma GWAS studies, revealed a significant association with SNP (rs6010620) in intron 12 of the RTEL1 gene, and amplification of the 20q13.33 region was observed in nearly 30% of gliomas, with copy-number changes correlating with RTEL1 expression levels [37, 38]. This evidence concerns the gene RTEL1 and central nervous system cancer.