 First, extrinsic stimulus through the TNF receptor by TNFα signals the recruitment of the TNF receptor-associated death domain (TRADD) which in turn recruits RIPK1.In the absence of active Caspase 8, RIPK1 and RIPK3 auto- and transphosphorylate each other, leading to the formation of a microfilament-like complex called the necrosome.The necrosome then activates the pro-necroptotic protein MLKL via phosphorylation.