Although the clinical implications chemotherapeutic agents such as temozolomide and irinotecan have shown improvements in regard to overall survival and quality of life, accumulating evidence suggests that nearly 50% of patients do not benefit from these drugs due to cellular resistance to chemotherapeutic agents, as well as O-6-methylguanine-DNA methyltransferase (MGMT) content in glioblastoma cells [16]. Here, MGMT is linked to glioblastoma.