Clinical trials focusing on blocking IL-6 signaling to treat COVID-19 benefit patients, including IL-6 receptor antagonists [tocilizumab (26, 27) and sarilumab (28)] and IL-6 inhibitors [siltuximab (29)], and tocilizumab needs to be combined with standard antiviral care to be highlighted in the comparison of international multi-center clinical trials (26, 30). Here, IL6 is linked to COVID-19.