IAP proteins were discovered in baculoviruses and are typically characterized by 2-3 baculovirus IAP repeats (BIR) and a RING finger motif.

• bcl-2有许多同源体，这些蛋白在体内通过同源、异源二聚体相互作用，而且促凋亡、抑制凋亡蛋白的相互比例决定着细胞对死亡刺激因素的最终敏感性。