PDCD1 and glioblastoma: In a glioblastoma (GBM) mouse model, G47Δ-mIL2 significantly prolonged median survival without systemic IL-2 toxicity (18).Another important study by a Chinese team focused on VG161(an engineered oHSV that expresses IL-12, IL-15, IL-15Rα and a PD-1-PD-L1-blocking fusion protein) in the phase I clinical trial of refractory hepatocellular carcinoma showed that there was no dose-limiting toxicity in 44 treated patients with refractory hepatocellular carcinoma, and the main side effect was fever (86.4%).