They also recruit mast cell progenitors and influence the accumulation of neutrophils and procollagen synthesis through fibroblasts.[31] In addition, CCL2 chemokines were expressed at higher levels in lung macrophages of severe COVID‐19 patients. CCL2 was upregulated early post‐SARS‐CoV‐2 infection. The gene discussed is CCL2; the disease is COVID-19.