While hypomethylation takes place in the repetitive region of the DNA that might be responsible for genomic instability contributing to tumor growth [7], hypermethylation of the MGMT (O6-methylguanine-DNA methyltransferase) promoter leads to MGMT epigenetic silencing in about 40% of GBM, which correlates with a better response to temozolomide (TMZ) treatment with an increase in median survival time [7,10]. Here, MGMT is linked to glioblastoma.