Genital chlamydia infection is controlled by the immune system, starting from the epithelial cells at the site of infection, which are the first to secrete proinflammatory cytokines/chemokines such as C-X-C Motif Chemokine Ligand 1 (CXCL1), IL-8, CXCL16, IL-6 and tumor necrosis factor (TNF)20–22. The gene discussed is TNF; the disease is infection.