CCL5 and COVID-19: Although in the present study, the measured levels of most of the cytokines and chemokines were higher in critical COVID-19 patients compared with those with milder symptoms, high levels of some of the cytokines and chemokines, namely, IL-7, platelet-derived growth factor (PDGF)-BB, regulated on activation, normal T cell expressed and secreted (RANTES), IFN-α2, and stem cell growth factor (SCGF)-β, were detected in some of the patients with milder symptoms.