Here is an up-to-date review of important new methods and results in anti-idiotypes, receptors, and molecular mimicry.It begins with a discussion of the theoretical background ofthe anti-idiotypic network, it's role in the regulation ofimmune response, and the physical characteristics ofanti-idiotypic antibodies. It then goes on to explore manyexciting applications in such areas as insulin action,thyroid cell function, the neurosciences, cardiology,virology, pharmacology, and reproduction.