We then validated the association between PDIA4 expression and the hallmark of angiogenesis in the TCGA-GBM cohort by gene set enrichment analysis (GSEA), and the results showed that the hallmark of angiogenesis was significantly enriched in high expression GBM of PDIA4 (Fig. 2C, NES = 2.483, adjusted p value < 0.0001). The gene discussed is PDIA4; the disease is glioblastoma.