Lactoferrin is an intriguing protein with an interesting structure and several known or suggested biological activities. We feel that attention on this protein has been too limited and diffuse, partly because it has been "hidden" among other well-known iron-binding proteins such as hemoglobin, ferritin and transferrin, but also perhaps because its biological functions are so diverse. Investigators that focus on lactoferrin represent a wide variety of medical and scientific disciplines that do not usually come together. It was our intention to improve that situation with this symposium. In this book, experts from a variety of disciplines describe the present knowledge of the structural features of lactoferrin, its carbohydrate side chains and its capacity to bind different metal ions and anions. Several of the possible physiological functions of lactoferrin are described in detail, including the role of lactoferrin in bacterial killing, its involvement in growth and proliferation, in immune function and in iron absorption. Aspects of the molecular biology of lactoferrin and its specific interactions with different cell types are also included. Finally, as lactoferrin now has become commercially available in larger quantities, possible industrial applications are discussed. The book should give the interested reader a thorough insight into our present knowledge of lactoferrin.