CXCL9 and oral cavity squamous cell carcinoma: In a previous study, we have used the multiplex suspension array system, a high-throughput proteomic platform, to measure 48 different cytokines/chemokines simultaneously and discovered that circulating plasma chemokine (C-X-C motif) ligand 9 (CXCL9) levels were significantly elevated in the patients with oral cavity squamous cell carcinoma and nasopharyngeal carcinoma [10], [11].