PLAUR and COVID-19: The highest level of PLAUR expression was detected in the lung monocytes/macrophages within all the studied cells (Figure 3A,C), and its expression was significantly decreased in alveolar macrophages AM1-2, monocyte-derived macrophages MoM1-2, and monocytes of COVID-19 patients (p < 0.001 for AM2 and p < 0.0001 for other cells vs. control, Figure 3A,C).