IL6 and COVID-19: Significant decreases in plasma concentrations of the pro-inflammatory cytokines IL-6, TNF, and IFN-γ, the leukocyte chemoattractants CXCL8, CXCL10, and CCL2, and the anti-inflammatory cytokines IL-10 and IL-1Ra were observed in COVID-19 patients during dexamethasone treatment (Figure 4C).