XIAP is a potent suppressor of apoptotic cell death. The BIR domain of XIAP binds directly to certain initiator and effector caspases,thus blocks the mitochondria death pathway.

• XIAP通过杆状病毒IAP重复序列(BIR)直接与起始以及效应caspases结合,抑制了细胞凋亡的线粒体途径,也可以通过NF-kB途径抑制细胞表面受体介导的凋亡。