CXCR6 and head and neck squamous cell carcinoma: Further survival analysis of these ligand–receptor pairs between epithelial subclusters and immune cells showed that the higher expression level of CXCL9, CXCL11, CXCL14, CXCL17, CXCR3, CXCR4, CXCR6, and GPR35 were correlated with better survival of patients with HNSCC (all p < 0.05; Fig. S3B).