IL6 and infection: Qin et al. (35) demonstrated the presence of lymphopenia, higher infection-related biomarkers (procalcitonin, erythrocyte sedimentation rate, serum ferritin, and CRP) and elevation of several inflammatory cytokines (IL-2R, IL-6, IL-8, IL-10, and TNF-α) in severe cases of COVID-19 as compared with non-severe ones.