In the tumour microenvironment (TME) of HNSCC, the levels of immune regulatory factors such as programmed cell death protein 1 (PD-1), PD-L1, and T cell immunoglobulin and mucin domain 3 (TIM-3) are upregulated (10), alongside the interplay of various cytokines (11). This evidence concerns the gene PDCD1 and head and neck squamous cell carcinoma.