NCT-504（Cat No.:I015455）is a small-molecule inhibitor identified as a selective modulator of phosphatidylinositol synthase (PIS), a key enzyme in phospholipid metabolism. By suppressing PIS activity, NCT-504 alters phosphatidylinositol levels and impacts downstream signaling pathways, including those related to membrane dynamics, vesicular trafficking, and cell survival. It has been explored in studies of autophagy, neurodegeneration, and cancer metabolism, where phosphoinositide regulation is critical. As a chemical biology probe, NCT-504 provides researchers with a powerful tool to dissect lipid signaling mechanisms and investigate therapeutic opportunities in metabolic and neurological diseases.