Considering that transfection of XIAP with mutated S-nitrosylation residue attenuates the cleavage of procaspase-9 induced by OGD/reoxygenation in SH-SY5Y cells, we confirm that transnitrosylation from procaspase-9 to XIAP plays an essential role during the apoptosis induced by cerebral ischemia-reperfusion or OGD/reoxygenation. Here, XIAP is linked to brain ischemia.