In certain tumor patients with MGMT promoter methylation or with reduced MGMT gene expression, such as malignant astrocytoma, glioma and diffuse large B-cell lymphoma, alkylating chemotherapy drugs can improve their survival rate.[25] This provides guidance for the use of new alkylating agents for HNC patients with MGMT promoter hypermethylation or MGMT protein deletion but with functional Mismatch Repair. This evidence concerns the gene MGMT and central nervous system cancer.