Besides detecting differences between LG and HG areas within the same tumor in grade 4 astrocytomas of validation cohort 2, we reported two major findings: (1) reduced HMGB2 expression in non-neoplastic glial cells and neurons, as previously reported [21,33,40,48]; and (2) a change in the subcellular HMGB2 expression from nuclear to cytoplasmic in infiltrating tumor cells. Here, HMGB2 is linked to astrocytoma (excluding glioblastoma).