IL6 and COVID-19: We searched MEDLINE, Embase, and MedRxiv from inception up to March 5, 2021, for clinical trials or meta-analyses evaluating the effect of interleukin-6 inhibitor treatment on patients with COVID-19 using the search terms (“COVID-19” OR “COVID” OR “SARS-CoV-2” OR “2019-nCoV” OR “coronavirus”) AND (“tocilizumab” OR “sarilumab” OR “interleukin-6 inhibitor” or “IL-6 inhibitor”).