PDCD1 and head and neck squamous cell carcinoma: Similarly, encouraging results were achieved from phase III trials testing anti-programmed cell-death-1/ligand-1 (PD-1/L1) immune-checkpoint inhibitors (ICIs) nivolumab10 and pembrolizumab,11 showing overall survival benefit for patients with recurrent/metastatic HNSCC irrespective of PD-L1 expression and HPV status.