Because of the unique immune-privileged features of the GBM TME, immune checkpoint inhibitors (CIs),which has managed to provide a new perspective in cancer therapy, failed to show significant clinical improvement, with the architecture of the ECM, especially the collagen, being linked with anti-programmed cell death-1 (PD1)/programmed cell death ligand-1 (PD-L1) resistance [21,22]. The gene discussed is PDCD1; the disease is cancer.