A comparison between COVID-19 patients with critical versus mild-moderate clinical condition revealed significantly higher cytokine and chemoattractant levels (IL-5, IL-6, IL-7, IL-13, IL-15, IL-18, TNF-α, CCL2, CCL3, CCL4) in critical patients (Fig. 1b and Suppl. This evidence concerns the gene CCL2 and COVID-19.