Shortly after the initial trial implementing TMZ as a therapeutical standard, Hegi et al. showed a benefit in survival for the subgroup of patients with high MGMT promoter methylation [26], a result that has been confirmed subsequently [28,29,30], and the MGMT promoter methylation has gained high significance as a prognostic biomarker and can inform therapeutical decisions both at initial diagnosis and at tumor progression [8,31,32,33,34]. The gene discussed is MGMT; the disease is neoplasm.