In two volumes, this book elucidates the crucial mechanisms that control the dynamics of phosphoinositide conversion. Starting out from phosphatidylinositol, a chain of lipid kinases collaborates to generate the oncogenic lipid phosphatidylinositol(3,4,5)-trisphosphate. For every phosphate group added, there are specific lipid kinases – and phosphatases to remove it. Additionally, phospholipases can cleave off the inositol head group and generate poly-phosphoinositols, which act as soluble signals in the cytosol. Volume I untangles the web of these enzymes and their products, and relates them to function in health and disease. Phosphoinositide 3-kinases and 3-phosphatases have received a special focus in volume I, and recent therapeutic developments in human disease are presented along with a historical perspective illustrating the impressive progress in the field.