Several of the clinical hallmarks of CRS are believed to be directly linked to macrophages activation: (i) hyperferritinemia due to release of apoferritin from macrophages, (ii) hypofibrinogenemia by release of plasminogen activator inhibitor, (iii) fever due to the release of IL-6, IL-β, and TNFα, and (iv) cytopenias due to the extensive release of interferon-γ [25,27,32]. The gene discussed is IL6; the disease is congenital rubella syndrome.