RIPK3 and viral infectious disease: For viral infection-induced necroptosis, RIPK3 and MLKL, but not RIPK1, are required and another protein, Z-DNA-binding protein 1 (ZBP1), also known as DNA-dependent activator of IFN regulatory factors (DAI), functions upstream of RIPK3-MLKL to initiate the formation of the necrosome [16].