Phosphoinositide-specific phospholipase C (PLC) plays a crucial role in the initiation of receptor mediated signal transduction through the generation of the two second messengers, inositol 1,4,5-triphosphate and diacylglycerol from phosphatidylinositol 4,5-bisphosphate. There are many mammalian PLC isozymes, including PLC beta1, PLC beta2, PLC beta3, PLC beta4, PLC gamma 1, PLC gamma 2, PLC delta1, PLC delta2 and PLC E. PLC gamma 1 is widely distributed in bronchiolar epithelium, type I and II pneumocytes and fibroblasts of the interstitial tissue. Actinregulatory protein Villin is tyrosine phosphorylated and associates with PLC gamma 1 in the brush border of intestinal epithelial cells. Villin regulates PLC gamma 1 activity by modifying its own ability to bind phosphatidylinositol 4,5-biphosphate. PLC gamma 1 binds alpha1beta1 Integrin and modulates alpha1beta1 Integrin-specific adhesion. PLC gamma 1 and Ca2+ play a direct role in VEGF-regulated endothelial growth, however this signaling pathway is not linked to FGF-mediated effects in primary endothelial cells.