Markers of neutrophilic activation, such as granulocyte colony-stimulating factor [G-CSF] and interleukin-8 [IL-8] and neutrophil-derived effectors (resistin [RETN], lipocalin-2 [LCN2]) had the greatest discriminatory power in this study for identifying patients with severe COVID-19 (5). This evidence concerns the gene RETN and COVID-19.