IL6 and COVID-19: Numerous studies stated that the severity of COVID-19 symptoms are correlated with elevated blood levels of proinflammatory cytokines and chemokines, e.g., IL-1b, IL-2, sIL-2RA, IL-6, IL-7, IL-17, IL-18, TNF-α, monocyte chemoattractant protein 1 and 3 (MCP-1 and 3), cytosolic carboxypeptidases 2 and 3 (CCL2 and 3), granulocyte colony-stimulating factor (G-CSF), interferon gamma-induced protein 10 (IP10), macrophage colony-stimulating factor (M-CSF) and microprotein 1a (MIP-1a) [44,45,46].