IL6R and COVID-19: Because IL-6 is a proinflammatory cytokine whose serum concentration is high in COVID-19, a humanized monoclonal antibody to the IL-6 receptor (IL-6R), TCZ, was granted an emergency authorization in June 2021 by the FDA, to treat inpatients with moderate and severe COVID-19, based on the results of two clinical trials, REMAP-CAP (NCT02735707) and RECOVERY (NCT04381936).