LCN2 and influenza: We further compared with sepsis and influenza to investigate disease specificity and found the plasma levels of G-CSF, IL-8, LF, CD163, LCN2, CCL20, IL-6, IL-10, CCL4, CCL19, TNF, and C5a were lower in critical and severe COVID-19 than sepsis (Figures 6E and S8G).