In September, 1989, the Editorial Board of Molecular and Cellular Endocrinology resolved to introduce a volume of brief, topical and rapidly published reviews as a new feature for 1990. As a compilation, this book contains twenty At The Cutting Edge reviews, and seven full-length reviews. It is likely that the same volume next year will contain twice as many reviews of At the Cutting Edge and half as many full-length reviews. There is a great deal of encyclopaedic review material detailing the evolution of the current state of knowledge in Molecular and Cellular Endocrinology, however, there is increasingly a place for a more challenging and up-to-the-minute and perhaps cross-disciplinary focus required as a supplement. At the Cutting Edge are essays on rapidly developing areas in contemporary endocrinology. These reviews are meant to be eclectic rather than exhaustive, and speculative rather than encyclopaedic. The purpose of these essays is to stimulate and challenge; and if reading them prompts an experiment that otherwise would not have been done, then they will have succeeded.
