Compared among histological subgroups, the level of LINE–1 methylation in As was significantly lower than that in oligodendroglial tumors, including OG and OA, which was similar to the MGMT promoter methylation (mean LINE-1 methylation level, 67.6% vs. 69.3%; p = 0.036, Figure 2B). Here, MGMT is linked to oligodendroglial tumor.