MGMT and glioblastoma: However, the survival benefit conferred by TMZ is largely restricted to patients with tumors that harbor a methylation of the MGMT gene promoter.12, 14 TTFields represent a novel treatment approach that has already been approved by FDA for newly diagnosed, as well as recurrent glioblastoma based on the results of two phase III trials.7, 8 However, there is a mismatch between the encouraging clinical data and the biological effects of TTFields on tumor cells, which have only been poorly understood.