Sema4A expression enhances B-cell infiltration, which contributes to favorable outcome for head and neck squamous cell carcinoma (28), and Sema4A expression on DCs activates CTL and exerts anti-tumor in Lewis lung cancer (29), whereas Sema4A maintains the stability and function of Tregs in melanoma (30). This evidence concerns the gene SEMA4A and head and neck squamous cell carcinoma.