TCGA GBM datasets show that higher expression of HA-related genes is correlated with lower survival rates. a Prognostic Index for HAS1, HAS2, RHAMM, and CD44 gene group, lowest quartile expression compared to highest quartile expression. Multi-gene prognostic indexes and hazard ratios determined with Cox model. b Prognostic Index for HAS1, HAS2, RHAMM, and CD44 gene group divided by GBM molecular subtypes