Although the hypomethylation frequencies of PRDM16 in higher-grade astrocytomas (WHO grades III and IV) were higher than those in lower-grade astrocytomas (WHO grades I and II) (Table 1), no statistical correlation was found between PRDM16 expression and sex, age or histological grade (Table 2). Here, PRDM16 is linked to astrocytoma (excluding glioblastoma).