BAP31 also kown as CDM, BCAP31 is a member of the B-cell receptor associated protein 31 superfamily. BAP31 plays a significant role in apoptosis regulation. BAP31 forms a protein complex that connects initiator caspases, such as procaspase-8, with anti-apoptotic proteins like Bcl-2 and Bcl-XL, thereby influencing cell survival and death pathways. The cytosolic domain of BAP31 features two identical caspase recognition sites, which are specifically cleaved by initiator caspases during apoptosis, resulting in the generation of a p20 fragment that remains membrane-integrated and acts as a potent inducer of cell death when ectopically expressed. This cleavage is vital for triggering cytoplasmic apoptotic events, including membrane fragmentation, and facilitates the interaction between mitochondria and the endoplasmic reticulum during Fas-mediated apoptosis.