Moderate quality of evidence showed that anti-interferon (IFN) was associated with increased risk of severity (OR=7.75; CI=1.79-33.61) and mechanical ventilation (OR=4.19; CI=2.06-8.53), but not with COVID-19 mortality (OR=1.68; CI=0.63-4.44). The gene discussed is IFNA1; the disease is COVID-19.