This monograph, aimed at graduate students and researchers in biology and related areas, deals with lectins, an exceedingly important class of diverse and widely occurring proteins that bind carbohydrates. They possess the unique ability to decode the information encoded in carbohydrates and thus to act as recognition determinants in diverse biological processes, both normal and pathological. Their study is therefore inextricably linked to glycobiology, a subject now in a stage of explosive growth. Since the publication of the first edition of this book in 1989, great strides have been made in several areas of lectin research. Numerous lectins have been isolated from a variety of sources, and their functions in infection, in inflammation and in immunity, both innate and acquired, have been clarified. In addition, the three-dimensional structures of close to 200 lectins, and of many of their complexes with carbohydrates has been elucidated, providing an insight into the molecu.