Mammalian platelets are small (2–4 um), discoid, short-lived fragments derived from megakaryocyte precursors. They play a crucial role not only in the formation of a normal hemostatic plug but they also play a key role in a much wider repertoire of physiological processes such as inflammation, innate immunity, cancer, infection, neurobiology, and tissue repair/regeneration. Over three sections, the individual chapters in this book identify one particular aspect of platelet function, dysfunction, or application. As significant advances continue to develop our thinking of the functional role of platelets in health and disease, this book elevates awareness and enthusiasm in further investigating these functions.