Similarly, infections with R. rickettsii, R. conorii, and R. africae caused the secretion of two chemokines, IL-8 and monocyte chemoattractant protein 1 (MCP-1, also known as CCL2) from endothelial cells, implying their roles in activating and recruiting neutrophils and monocytes to the sites of infection (75, 77, –, 79). The gene discussed is CCL2; the disease is infection.