Aimed at advanced undergraduates, postgraduates and researchers, this important textbook provides a detailed description of the structure and mechanisms of phosphoinositide 3-kinase (PI3Ks) signalling of all classes, with focus on the cellular context of PI3K activity, including its relevance to normal tissue and diseased states.This book contains a general review chapter detailing the mechanisms of cell proliferation and apoptosis, which are two of the main cellular targets of PI3K signalling. In addition, it provides a detailed description of the role of PI3K on the regulation of FOXO proteins, which are now becoming one of the most closely studied and important proteins in the regulation of cell death, cell proliferation and senescence.