Finally, concordance between increased levels of some NF-κB–dependent biomarkers (MCP-1/CCL2, MIP-1α/CCL3, IL-6, and sTNFRSF1A) and the NF-κB–associated transcriptional score in whole blood strongly suggests that circulating hematopoietic cells significantly contribute to the systemic inflammatory response during COVID-19. The gene discussed is CCL2; the disease is COVID-19.