FCN1 and COVID-19: The transcriptomic signature of major regulators of innate immunity (monocytes, neutrophils, and macrophages) in severe COVID-19 indicates different immune profiles among COVID-19 patients: Liao et al. showed abundant macrophages expressing FCN1 in BAL of COVID-19 patients, whereas He et al. noticed only a minor increase in FCN1+ macrophages, with a significant decrease in FCN1+ monocytes/neutrophils (59, 60).