CXCR6 and head and neck squamous cell carcinoma: In the evaluation of the independent prognostic values of CXCR3 to CXCR6 along with the controlling of prognostic effects of these clinical features, the independent prognostic biomarkers of HNSCC outcome were reported by multivariate Cox proportional hazards regression analysis, i.e., the expression of CXCR3 to CXCR6 and two clinical parameters (age and stage) (Fig. 4).