Used in research as a potent and selective inhibitor of Bcl-2 family protein Bcl-xL, A-1331852 is primarily applied in oncology studies to induce apoptosis in cancer cells. It shows particular utility in models of solid tumors and hematological malignancies where Bcl-xL overexpression contributes to cell survival and drug resistance. Due to its selectivity, it allows scientists to dissect the role of Bcl-xL without significant off-target effects on related proteins like Bcl-2. The compound is also employed in combination therapies to enhance the efficacy of chemotherapeutic agents and overcome resistance mechanisms. Its application remains confined to preclinical research, supporting target validation and mechanistic studies in cancer biology.