The percentage of neutrophils expressing CD54, a marker of reverse transmigration, was elevated in COVID-19 patients compared to both AMC and CAP patients (26% (37) AMC vs. 71% (21) COVID-19, p < 0.0001, vs. 7% (11) CAP, p < 0.0001, Figure 4C). Here, ICAM1 is linked to COVID-19.