HMGB2 and astrocytoma (excluding glioblastoma): Clinical validation of our results and of the IHC method for HMGB2 assessment in larger, independent cohorts and in CLIA-certified (or equivalent) facilities is needed to validate our findings and establish HMGB2 as prognostic biomarker of grades 2 and 3 astrocytoma evolution and predictive biomarker of response to treatment in grade 4 astrocytomas.