Among them, anti-programmed cell death protein 1 (PD-1) agent pembrolizumab monotherapy or combination therapy has been approved as the first line for relapse/metastasis HNSCC, and it prolongs the median overall survival (OS) by between 0.8 months and 2.3 months [4,5]. This evidence concerns the gene PDCD1 and head and neck squamous cell carcinoma.