IL6 and COVID-19: Severe COVID-19 patients, in comparison to moderate individuals, showed 18 plasma biomarkers (D-dimer, ferritin, IP-10, NT-proBNP, MCP1, IFN-γ, MIG, M-CSF, IL-4, IL-7, IL-6, MIP-1, FGF-2, TIM3, HGF, IL-8, IL-10, and TNF-α).