IFNA2 and COVID-19: Specifically, the samples were categorized into three groups: Group 1 consisted of patients with neutralizing antibodies to IFN-α2 or IFN-ω and was named the NaAb( +) group, Group 2 and 3 are both NaAb(-) groups that lack such autoantibodies, included patients with life-threatening and no-life-threatening COVID-19, respectively.