MGMT and central nervous system cancer: In conclusion, our study in Indonesian patients with glioma showed that 21.7% of patients with glioma harbor IDH1 mutations, but no IDH2 mutations. IDH1 mutation is significantly associated with smoking, frontal lobe involvement, oligodendroglial histology, grades II and III tumors, lower Ki67 expression, methylation of MGMT promoter, shorter interval between onset of symptoms and initial surgical interventions, and longer OS.