Is IL-6 a key cytokine target for therapy in COVID-19?

The identification of elevated IL-6 levels in patients with severe COVID-19 led to the rapid development of clinical trials targeting this cytokine. Overall, these trials do not support the widespread use of IL-6 antagonists in hospitalized patients with mild-to-moderate disease, but IL-6 antagonists may be beneficial when rapidly deployed in patients with severe COVID-19, as we discuss here.