EPB41L3 and oligodendroglial tumor: In astrocytic and oligodendroglial tumors, EPB41L3 hypermethylation was a prognostic factor of poor survival (p = 0.035), and TSP-1 hypermethylation is a strong prognostic factor in oligodendroglioma, associated with prolonged survival (p = 0.003) (Table 4).