Among the 19 potential variables, percutaneous oxygen saturation (SpO2) <92% (odds ratio [OR] 7.50, 95% confidence interval [CI] 2.806–20.82) and IL-6 (OR 1.021, 95% CI 1.010–1.033) were included in developing the risk score, which was termed interleukin (IL)-6-based COVID-19 severity (IBC-S) score. This evidence concerns the gene IL6 and COVID-19.