BIX is widely used as a selective inhibitor of the E3 ubiquitin ligase, particularly targeting the XIAP (X-linked inhibitor of apoptosis protein) family. It promotes apoptosis in cancer cells by blocking the anti-apoptotic activity of XIAP, making it a valuable tool in cancer research, especially in studies involving cell death pathways and tumor suppression. BIX is also applied in neurodegenerative disease models where controlled regulation of apoptosis is needed. Its ability to cross the blood-brain barrier enhances its utility in central nervous system-related studies. Additionally, BIX has been used in combination therapies to sensitize resistant cancer cells to conventional treatments such as chemotherapy and radiation.