BILN-2061 is primarily used in the field of medical research, particularly in the study and development of antiviral therapies. It has shown significant potential in inhibiting the replication of certain viruses, making it a valuable compound in the fight against viral infections. Researchers have utilized BILN-2061 to explore its efficacy against hepatitis C virus (HCV), where it acts as a protease inhibitor, disrupting the virus's ability to replicate and spread within the host. This has paved the way for further studies aimed at developing more effective treatments for HCV and potentially other viral diseases. Additionally, BILN-2061 serves as a crucial tool in understanding the mechanisms of viral protease enzymes, contributing to the broader field of antiviral drug discovery.