The G500 allele is more frequent in GBMs without a definitive telomere maintenance mechanism.

n, number of individuals; non-tumor cohort, controls selected from the same general population; non telomerase-ALT, GBM negative for telomerase activity and ALT. The number of individuals with each genotype is given in parentheses;
**, p = 0.007, non telomerase-ALT versus telomerase positive, Odds Ratio 0.333, 95% CI 0.156–0.732; p = 0.002, non telomerase-ALT versus telomerase and ALT combined, Odds Ratio, 0.312, 95% CI 0.152–0.643; p = 0.001, non telomerase-ALT versus the non-tumor cohort selected from the same general population, Odds Ratio 0.365, 95% CI 0.2–0.67. All comparisons were tested using the Fisher's exact test p<0.05 was taken as a significant difference.