PDCD1 and head and neck squamous cell carcinoma: In an analysis of 114 patients with R/M HNSCC who received anti-PD-1 antibody treatment, ORR (30.6% vs 12.3%, p=0.02), PFS (6.9 vs 2.1months, p=0.0004)and OS (12.5 vs 6.8months, p=0.0007) in patients with irAEs were improved compared with those without irAEs.