Both transcriptional silencing of the MGMT gene by methylation of the CpG dinucleotides (CpGs) in the promoter region as well as absence of MGMT protein have been associated with a good clinical response to alkylating agents in general and in particular to TMZ in patients with an anaplastic astrocytoma or GBM (Esteller et al, 2000; Hegi et al, 2005; Chinot et al, 2007; Nagane et al, 2007; Sadones et al, 2009). This evidence concerns the gene MGMT and glioblastoma.