. "PI3K's preferred substrate is phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] which is phosphorylated to the trisphosphate [PI(3,4,5)P3]. PI3-kinase and its products have been found to be of importance in PDGF-stimulated actin reorganization, and directed cell movement, as well as in the stimulation of cell growth and inhibition of apoptosis."^^ . . . .