Used primarily as a folate antagonist in medical research and cancer treatment, this compound functions as a potent inhibitor of dihydrofolate reductase (DHFR), an enzyme critical for DNA synthesis and cell division. It is employed in the study of antifolate resistance mechanisms and serves as a key intermediate in the development of targeted chemotherapeutic agents. Its structure allows for selective activity against rapidly dividing cells, making it valuable in oncology research, particularly in the design of drug conjugates for tumor-specific delivery. Additionally, it has been explored in autoimmune disease research due to its immunomodulatory effects.