CRS arises as a direct consequence of overactivation of the immune system, which leads to a substantial increase in various serum cytokines, such as interleukin-6 (IL-6), interferon gamma (IFN-γ), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-1 (IL-1), or monocyte chemoattractant protein 1 (MCP-1) (6, 12–16). Here, CSF2 is linked to congenital rubella syndrome.