SU9516 is primarily used in biomedical research as a selective inhibitor of cyclin-dependent kinases (CDKs), especially CDK2. It is employed to study cell cycle regulation and to investigate the role of CDK2 in cancer cell proliferation. Due to its ability to induce cell cycle arrest and apoptosis in tumor cells, SU9516 serves as a tool compound in developing anticancer therapies. It is also used in combination studies with other kinase inhibitors to assess synergistic effects and overcome drug resistance in various cancer models. Its application remains confined to laboratory research and is not used in clinical settings.