Out of twenty-five methylation probes located in the region of HMGB2, hypermethylation of six probes were strongly associated with reduced HMGB2 expression; hypermethylation of three of those probes (cg1937134, cg21499459 and cg08269316), all located in the gene body, were also significantly associated with better OS (Supplementary Table S9 and Figure S3), substantiating that lower HMGB2 expression is related to better survival in grades 2 and 3 gliomas. This evidence concerns the gene HMGB2 and central nervous system cancer.