Secondly, patients in Ahmadi’s study were treated with nitrosourea-based chemotherapy as adjuvant treatment but in Hartmann’s study which demonstrated survival benefit of IDH1 mutated LGG, adjuvant treatment was alkylating agents.Additionally, in contrast to most studies about IDH1/IDH2 mutation in gliomas in the literature which investigated primary samples, we studied paired primary and recurrent gliomas. The gene discussed is IDH1; the disease is central nervous system cancer.