IFNG and head and neck squamous cell carcinoma: Among the 49 significant DEGs in the NOM, SIN, and HNSCC groups (Fig. 4b, Online Resource 6), the hypoxia-inducible factor-1 alpha (HIF-1α) and interferon-gamma (IFN-γ) pathways were significantly upregulated in HNSCC compared to NOM and SIN, with further upregulation observed relative to SIN (Online Resource 7).