Individual marker expression by neutrophils was less able to discriminate healthy controls and patients with mild COVID-19 and severe COVID-19 (Supplemental Figure 2), though findings were consistent with the clustering-informed gating, with a clear stepwise increase in CD10lo (Supplemental Figure 2A) and decrease in CXCR2 expression (Supplemental Figure 2B), respectively with COVID-19 disease severity. The gene discussed is CXCR2; the disease is COVID-19.