Tocelebrate the 40th anniversary of the discovery of Natural Killer (NK) cells,this volume focuses on the recent advances in our understanding of NK cell developmentand differentiation and their acquisition of functional properties, as well asthe latest models for NK-cell analysis in mice and applications in clinicalmedicine. NK cells have travelled a circuitous path from their initialdescription as 'spontaneous killers' (for some simply an experimental artifact)to being a bona fide subset of innatelymphoid cells with a complementary mode of action in immune defense and animportant mediator of immune reactivity in health and disease. Together, thesereviews provide a timely and concise picture of the evolution of NK cells asessential agents in immunity and as potent weapons against disease. This bookoffers an appealing and insightful resource for scientists and clinicians.