PDCD1 and glioblastoma: In addition, engineered autologous TILs that secrete antibodies targeting PD-1 (PD-1-TILs, aiming to prevent infused T-cell exhaustion induced by PD-1-mediated immunosuppression) are well tolerated, with no unexpected high-grade adverse events in GBM patients, and show improved antitumor efficacy compared with that of normal TILs, representing a new TIL treatment strategy for GBM [51].