Peripheral blood and lungs of SARS patients were characterized by elevated levels of proinflammatory cytokines, such as IL-1, IL-2, IL-6, IL-8/CXCL8, and chemokines, including CXCL10 and MCP-1/CCL2, which were associated with disease severity (10–14). Here, CCL2 is linked to severe acute respiratory syndrome.