It is characterized by the elevation in serum levels of multiple pro-inflammatory cytokines including IL-6, IL-8, IL-10, IFN-γ, TNF-α, granulocyte-colony stimulating factor (G-CSF) etc. [66, 67] In SARS-CoV and MERS-CoV, CRS was discovered to be the major cause of fatality, probably by inducing ARDS and secondary hemophagocytic lymphohistiocytosis (sHLH) [68, 69]. Here, IL6 is linked to acute respiratory distress syndrome.