PDCD1 and glioblastoma: The results demonstrated that SERPINE1 expression was positively correlated with the expression of most inhibitory immune checkpoints, including CD274 (PD-L1), PDCD1 (PD-1), CTLA4, and HAVCR2 (TIM-3) in most cancers, especially GBM-LGG, KIPAN, UVM, PAAD, and COAD-READ (Figure 8A).