PF-543 is a potent and selective inhibitor of phosphatidylinositol-4-phosphate 5-kinase alpha (PIP5Kα), an enzyme involved in the synthesis of phosphatidylinositol-4,5-bisphosphate (PIP2), a key signaling lipid. It is widely used in cellular and molecular biology research to study phosphoinositide signaling pathways. Its primary application lies in probing the role of PIP2 in processes such as membrane trafficking, cytoskeletal reorganization, and cell migration. By selectively inhibiting PIP5Kα, PF-543 helps researchers dissect the contribution of this enzyme in cancer cell proliferation and invasion, particularly in studies involving glioblastoma and other solid tumors. It is also employed in studies of insulin signaling and glucose uptake, where PIP2 dynamics play a regulatory role. Due to its high selectivity and cell permeability, PF-543 is valuable for in vitro assays and cellular models, though its use in vivo is limited by pharmacokinetic properties. Overall, PF-543 serves as a critical tool compound for understanding lipid kinase networks and their implications in disease mechanisms.