MK591 free acid is primarily used in research settings to study the role of leukotrienes in various physiological and pathological processes. It acts as a potent and selective inhibitor of 5-lipoxygenase-activating protein (FLAP), thereby blocking leukotriene biosynthesis. This makes it valuable in investigating inflammatory conditions such as asthma, allergic reactions, and other respiratory disorders. Researchers utilize it to understand the mechanisms of leukotriene-mediated inflammation and to explore potential therapeutic interventions. Additionally, it is employed in preclinical studies to evaluate the efficacy of new anti-inflammatory drugs and to assess the impact of leukotriene inhibition on disease models. Its application helps advance knowledge in immunology and pharmacology, contributing to the development of targeted treatments for inflammatory diseases.