Apoptotic cell death controls proper lymphocyte development and destruction of autoreactive lymphocytes, and defects in apoptotic destruction of these autoreactive lymphocytes result in autoimmune diseases [21]: TNFR-dependent extrinsic apoptosis is crucial for the negative selection of autoreactive thymocytes, and antiapoptotic BCL2 family members play a role in regulation of this process [22–25]; BCL2 family signaling contributes to selection against polyreactive B cells [26–28]. Here, BCL2 is linked to autoimmune disease.