Levels of serum IL-10 (p = 0.0001), IL-6 (p = 0.002), MIP-3α (p = 0.02) and CD40-L levels (p = 0.002) significantly increased from 5 to 9 day of illness to 10–21 day of illness in patients with moderate-to-severe COVID-19, but not in those with mild illness. The gene discussed is CCL20; the disease is COVID-19.