Necrostatin-1 is a potent and selective inhibitor of necroptosis, a mechanism of programmed cell death separate from apoptosis. Necrostatin-1 functions as an allosteric inhibitor of the death domain receptor-associated adaptor kinase RIP (RIP1) in the necroptosis pathway. While affecting this distinct cell death pathway, Necrostatin-1 does not present any perturbation of the Fas/TNFR triggered canonical apoptosis cascade. Necrostatin-1 inhibits RIP1 kinase the key upstream kinase involved in the activation of necroptosis (EC50=180nM).