Used in research and therapeutic development targeting viral entry inhibition, particularly in respiratory viruses like SARS-CoV-2. Blocks the activity of transmembrane serine protease 2 (TMPRSS2), preventing spike protein priming and viral fusion with host cell membranes. Investigated for potential in treating viral infections where TMPRSS2 plays a key role in pathogenesis. Employed as a reference in antibody screening, assay development, and comparative studies for drug discovery.