Among the 40 cytokines detected and compared between TB and non-TB patients, 8 cytokines including I-309/CCL1, RANTES/CCL5, MCP-2/CCL8, IL-8/CXCL8, MIG/CXCL9, MCP-1/CCL2, IFN-γ and PDGF-BB were significantly higher expressed in TB-PEs. This evidence concerns the gene CXCL9 and tuberculosis.