Regarding the gene alterations among specific types of tumors, high incidence of loss of chromosome 1p and 19q and methylation of several genes, such as MGMT, estrogen receptor gene, RB1, TP73, TP14, TP15, and TP16, have been found to be characteristics of oligodendroglial tumors. This evidence concerns the gene MGMT and oligodendroglial tumor.