TBK1 and viral infectious disease: Viral infection of respiratory epithelial cells activates a number of signaling cascades including tank binding kinase 1 (TBK1), inhibitor-kB kinase ε (Ikkε), and IRF3, resulting in the secretion of effector molecules including IFNs and ISGs to induce an antiviral state (12, 14, 54, 55).