This volume describes the current status of the biology of inositols and phosphoinositides with an emphasis on the development in the area since the publication of volume 26 in 1996 in this series. The progress made in dissecting the genetics, structure and evolution of the seminal enzyme for synthesis of inositol in the biological system has driven the understanding of the enzyme forward. With the current genomic and proteomic tools in place the new role of inositols, inositol phosphates and phosphoinositides in cell signaling or stress response has been explored. These advances are described in this volume and are expected to give new insights into the functional implications of inositol compounds across evolutionary diverse species.