Meta-analyses on 71 studies comprising 29,495 patients showed that mortality, mechanical ventilation and the composite endpoint of mechanical ventilation and mortality were lower for COVID-19 patients treated with IL-6 (receptor) antagonists compared to COVID-19 patients who were not treated with IL-6 (receptor) antagonists, whereas the risk of neutropenia, impaired liver function and secondary infections were higher for patients treated with IL-6 (receptor) antagonists compared to patients not treated with treated with IL-6 (receptor) antagonists. Here, IL6 is linked to COVID-19.