In the presence of an infectious agent, leucocytes and epithelial cells produce chemoatractants, cytokines (e.g., IL-8, IL-1, TNF-α) and acute phase proteins (e.g., haptoglobin [Hp], serum amyloid A [SAA]), that attract neutrophils to the site of the infection. The gene discussed is CXCL8; the disease is infection.