CCL2 and meningitis: The serum proinflammatory cytokines in STSS patients, especially interleukin 6 (IL-6), IL-1β, and tumor necrosis factor (TNF), gamma interferon (IFN-ɣ), IL-12, and monocyte chemoattractant protein 1 (MCP-1), are significantly higher than those in meningitis patients (Ye et al., 2009).