CXCL8 and COVID-19: In keeping with increased levels of biomarkers associated with neutrophil activation and increased IL-8 levels, the MFI of the granule protein CD66b was greater and the MFI of the IL-8 receptor CXCR2 was lower in peripheral blood neutrophils of COVID-19 patients (n = 2) relative to HVs (Supplemental Figure 8), and peripheral blood neutrophils of COVID-19 patients exhibited pronounced vacuolization (Supplemental Figure 5B).