HIF1A and glioblastoma: GBM and peritumoral tissue significantly differed for HIF1α- (Figure 1K; p = 0.001, Mann-Whitney test), HIF2α- (Figure 1L; p < 0.001, Mann-Whitney test), VEGF- (Figure 1M; p < 0.001, Mann-Whitney test) and VEGFR1- (Figure 1N; p = 0.013, p < 0.001, Mann-Whitney test) positive cell density, with higher values found in GBM than in the peritumoral tissue, while no difference was observed in the density of cells expressing VEGFR2 (Figure 1O; p = 0.48, Mann-Whitney test).