Hypermethylation of the MGMT promoter and associated loss of expression correlates with response to temozolamide and BCNU in primary gliomas (Esteller et al, 2000; Paz et al, 2004) and is an independent predictor of overall and progression-free survival in patients with diffuse large B-cell lymphoma treated with cyclophosphamide-containing regimens (Esteller et al, 2002). Here, MGMT is linked to central nervous system cancer.