SERPINE1 and glioblastoma: Although genes (TTR, SERPINE1, ACTA2, APOA1) encoding transthyretin, α1-antitrypsin, actin and apolipoprotein A1 respectively, were not significantly associated with overall survival, we note that all TCGA GBM transcriptomic data represents samples derived from the proliferative core and not infiltrative margin.