Nafamostat dimethanesulfonate (also known as Nafamostat mesilate or FUT-175) is a potent, broad-spectrum synthetic serine protease inhibitor. It targets enzymes including thrombin, trypsin, kallikrein, factor Xa, plasmin, urokinase, and complement factors. Primarily utilized in biochemical and pharmacological research to study protease roles in coagulation, fibrinolysis, inflammation, and complement activation. Clinically approved in Japan for acute pancreatitis treatment and as an anticoagulant in disseminated intravascular coagulation (DIC) and extracorporeal circulation. Also investigated for antiviral (e.g., TMPRSS2 inhibition in SARS-CoV-2) and anticancer applications via tumor-associated protease inhibition.