CD4 and head and neck squamous cell carcinoma: The amount of six TII cell types (B cells, CD4 T cells, CD8 T cells, neutrophils, macrophages, and dendritic cells) in the tumor microenvironment of HNSCC, LuSCC, and CeSCC was estimated using Tumor IMmune Estimation Resource (TIMER), a web resource for the evaluation of clinical relevance of tumor-immune infiltration.