SJ-172550 is primarily used in biochemical research to study the mechanisms of apoptosis, particularly in cancer cells. It functions as an inhibitor of MDMX, a protein that negatively regulates the tumor suppressor p53. By inhibiting MDMX, SJ-172550 helps to activate p53, leading to the induction of apoptosis in cancer cells. This makes it a valuable tool for understanding the role of the p53 pathway in tumor suppression and for developing potential cancer therapies. Researchers also use it to explore the interactions between MDMX and p53, as well as to identify new targets for anticancer drug development. Its application is largely confined to laboratory settings, where it aids in the discovery of novel therapeutic strategies for treating cancers with dysregulated p53 activity.