CXCL9 and head and neck squamous cell carcinoma: In order to test the effects of EGFR signaling on T cell attraction, we used the two HPV-negative UM-SCC4 and UM-SCC19 and the two HPV-positive HNSCC cell lines UM-SCC47 and UM-SCC104 for the expression of CCL2, CCL5, CXCL9, CXCL10, IL-6 and IL-1β by qPCR.