Serum CCL2, CCL3, CCL7, CXCL9, CXCL10, IL-1β and IL-1Ra levels increased in critical COVID-19 patients (n = 11) when compared to both severe COVID-19 patients (n = 25) and moderate COVID-19 patients (n = 14). The gene discussed is CXCL9; the disease is COVID-19.