TNF and viral infectious disease: Currently, one of the best studied form of necroptotic cell death is initiated by tumor necrosis factor (TNF), but necroptosis can also be induced by other members of the TNF death ligand family (Fas and TNF-related apoptosis-inducing ligand (TRAIL)), interferons (IFNs), Toll-like receptors (TLRs) signaling and viral infection via the DNA sensor DNAdependent activator of interferon regulatory factor (DAI).3 Here we take TNF as an instance to elaborate on the signal pathway of necroptosis.