IL6 and COVID-19: We performed a preliminary analysis ourselves in EDTA plasma samples from ICU patients with COVID-19 using the Simoa 6-plex cytokine assay (data not shown), which confirmed that median IL-6 level is >tenfold higher in ICU patients as compared with the samples used in the current study, while the other cytokines were between twofold and fourfold higher in the ICU samples compared with the samples of the current study.