IL6 and COVID-19: For most severe patients with COVID-19, the levels of pro-inflammatory cytokines soared in the serum, similar to that in SARS and MERS, including IL-6, IL-1β, IL-2, IL-8, IL-17, G-CSF, GM-CSF, IP10, MCP1, MIP1α, and TNF-α (8, 49–53).