Their study showed that a cytokine spectrum of IFN-γ, IL-6, IL-8, sIL-2Rα, sgp130, sIL-6R, MCP1, MIP1-α, MIP1-β and GM-CSF could be used as a predictive model for severe CRS; elevation of IFN-γ and sgp130 is strongly associated with grade 4–5 CRS. This evidence concerns the gene CCL2 and congenital rubella syndrome.