MGMT and glioblastoma: While focusing on GBMs and adjusted for age, gender, and TMZ treatment, only TERT-mut GBM patients with MGMT methylation appeared to benefit from TMZ treatment (HR = 0.33; 95% CI = 0.23–0.47; I2 = 44%), whereas MGMT methylation did not appear to be associated with improvement in OS in TERT-wt GBMs (HR = 0.80; 95% CI = 0.56–1.15; I2 = 0%) (Fig. 3).