MGMT and neoplasm: As a consequence, the cytotoxic impact of TMZ can be neutralized quite effectively when MGMT is present.5,6 It was therefore not entirely surprising to find that those patients with epigenetic MGMT gene silencing in their tumor tissues received a substantially greater benefit (mOS = 21.7 months) in response to treatment with the Stupp protocol than patients with an active (unmethylated) MGMT promoter (mOS = 12.7 months).