Among the other prototypical chemoattractant receptors present on neutrophils, the expression of complement receptor C5aR was significantly decreased (Figure 3D and Supplemental Figure 1F) whereas the formyl peptide receptors FPR1 and FPR2 were significantly increased on COVID-19 BAL fluid neutrophils (Figure 3, E and F, and Supplemental Figure 1G), in comparison with blood neutrophils. Here, FPR2 is linked to COVID-19.