CXCL9 and head and neck squamous cell carcinoma: The cohorts of GSE10332 and GSE139324 (the GSE10332 cohort contained all kinds of cells in TME, while the GSE139324 cohort only contained infiltrative leukocytes) were applied for the relationship assay at the single cell level to disclose the effects of CXCL9, CXCL10, CXCL11, and CCL5 on the HNSCC sub-populations in TME.