APAF1, also named as Apoptotic protease-activating factor 1 or KIAA0413,it is a cytoplasmic protein that initiates apoptosis. This protein contains several copies of the WD-40 domain, a caspase recruitment domain (CARD), and an ATPase domain (NB-ARC). APAF1 localizes in the cytoplasm and is widely expressed in many tissues.