PF-543 Citrate is primarily used in biochemical research to study the role of sphingosine kinase 1 (SphK1) in cellular processes. It acts as a potent and selective inhibitor of SphK1, an enzyme involved in the production of sphingosine-1-phosphate (S1P), a lipid signaling molecule. By inhibiting SphK1, researchers can investigate the enzyme's impact on inflammation, cancer progression, and immune responses. This compound is valuable in understanding the signaling pathways associated with S1P and its role in diseases such as cancer, fibrosis, and inflammatory disorders. It is also used to explore potential therapeutic strategies targeting SphK1 in preclinical studies.