IL6 and COVID-19: The host immune response of COVID-19 suggests an immune signature consisting of elevated serum cytokines (IL-6 and TNF-α); elevated inflammatory serum markers including ferritin, lactate dehydrogenase (LDH), D-dimer, C-reactive protein (CRP), and coagulation factors; impaired interferon responses; and peripheral lymphopenia [3,9,10].