ABT-263 is primarily utilized in the field of oncology as a potent inhibitor of Bcl-2 family proteins, which play a crucial role in regulating apoptosis, or programmed cell death. By targeting these proteins, ABT-263 promotes the death of cancer cells, particularly in tumors that rely on Bcl-2 for survival. It has shown promise in preclinical and clinical studies for treating various hematologic malignancies, such as chronic lymphocytic leukemia (CLL), as well as small cell lung cancer (SCLC). Additionally, ABT-263 is being investigated for its potential to enhance the efficacy of other cancer therapies, including chemotherapy and radiation, by overcoming resistance mechanisms in cancer cells. Its ability to selectively induce apoptosis in cancer cells while sparing normal cells makes it a valuable candidate for targeted cancer treatment strategies.