CCL2 and opsoclonus-myoclonus syndrome: To further investigate the effects of serum IgG from children with OMS and NB on microglial activation, the concentrations of proinflammatory cytokines (including IL-1β, IL-6, TNF-α, and MCP-1) and NO in the media of cerebral cortical and cerebellar microglias were detected by ELISA.