Due to the cytokine storm, high levels of proinflammatory cytokines circulate to other tissues, establishing multi-organ damage, with severe and critical COVID-19 exhibiting considerably increased serum levels of proinflammatory cytokines including IL-6, IL-1β, IL-10, IL-2, IL-8, IL-17, granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), IP10, MCP-1, MIP1-α, IFN-γ, and TNF, which is thought to be the major cause of disease severity and death in COVID-19 patients (56) (Figure 1). Here, IL6 is linked to COVID-19.