STMN1 and pilocytic astrocytoma: A significant difference in STMN1 expression levels was also observed among the groups (p < 0.0001), and diffusely infiltrative astrocytomas (AGII to IV) presented higher expression levels than non-invasive pilocytic astrocytomas (AGI) (p < 0.0005, p < 0.0005 and p < 0.05, respectively).