Although, several studies have shown that a deficiency of DNA repair enzyme, O6-methylguanine methyl-DNA transferase (MGMT) can increase the sensitivity of glioma to Carmustine [29-31], many tumors with low levels of MGMT are nevertheless chemoresistant [32,33], suggesting the involvement of other unknown mechanisms of chemoresistance. This evidence concerns the gene MGMT and central nervous system cancer.