PECAM1 and glioblastoma: However, CD31 staining differed between the two therapy methods: compared to the LV-Ctrl GBM subgroup, and no significance differences were observed in the LV-PDIA4 group (Fig. 6J-K), which further demonstrated that antiangiogenetic therapy was effective in GBM with lower expression of PDIA4 than in GBM with higher expression of PDIA4.