In this book, the major paradigm-shifting discoveries made in the past century on key cellular nanomachines are described in great detail: their complex yet precise and elegant design and function, as well as the diseases linked to their dysfunction and the therapeutic approaches to overcome them. The major focus of this book is the "porosome" nanomachine, the universal secretory portal in cells. This is an ideal book for students, researchers, and professionals in the fields of nanoscience and nanotechnology.