We could not detect a major transcriptional up-regulation of the IL6R mRNA in immune cells from COVID-19 patients (Supplementary Figure S1), and as the major mechanism of sIL-6R generation is proteolysis (18), the increase in sIL-6R in both patient groups is therefore most likely due to enhanced proteolysis, which is in line with a previous study showing more IL-6R shedding induced by the SARS-CoV-2 spike protein (62). Here, IL6R is linked to COVID-19.