Compared to SOD2 16Val homozygotes, carriers with the SOD2 16Ala allele exhibited a more than 1.86-fold increased risk of glioma occurrence (adjusted OR = 1.86; 95% CI = 1.35-2.55), where the risk increased significantly with the increasing number of variant alleles (P-trend < 0.001). This evidence concerns the gene SOD2 and central nervous system cancer.