CRS (Table 1) is caused by generalized immunological activation and is associated with significant increases in inflammatory cytokines such as granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6) (Figure 3). Here, TNF is linked to congenital rubella syndrome.