MGMT and brain cancer: Because MGMT repairs the mutagenic and cytotoxic O6-alkylguanine adducts generated by the clinically used anticancer alkylating agents, it has emerged as a central and rational target for overcoming tumor resistance to alkylating agents [4,5]; this is particularly true for brain cancers because the hydrophobic monofunctional and bifunctional alkylating agents that cross the blood–brain barrier and generate O6-methyl/alkyl guanines in DNA remain the drugs of choice for this tumor type [6].