NFKB1 and viral infectious disease: However, A20 is a potent inhibitor of NF-κB-, TLR3-, and retinoic acid-inducible gene I-mediated IFN induction; thus, along with increased activation of NF-κB, interferon regulatory factor (IRF)-3, and IRF7, viral clearance was improved in A20-deficient cells, and this deficiency may protect the host against viral infection [118, 119].