LY294002 is a morpholine derivative of quercetin. It is a potent inhibitor of phosphoinositide 3-kinases (PI3Ks). PI3Ks (phosphatidylinositol 3-kinases) is an enzyme implicated in growth factor signal transduction by associating with receptor and nonreceptor tyrosine kinases, including the platelet-derived growth factor receptor. Inhibitors of PI3Ks could potentially give a better understanding of the function and regulatory mechanisms of the enzyme. The PI3Ks (phosphatidylinositol 3-kinases) regulate cellular signaling networks that are involved in processes linked to the survival, growth, proliferation, metabolism and specialized differentiated functions of cells. The subversion of this network is common in cancer and has also been linked to disorders of inflammation. The elucidation of the physiological function of PI3K has come from pharmacological studies, which use the enzyme inhibitors Wortmannin and LY294002, and from PI3K genetic knockout models of the effects of loss of PI3K function.