The biochemistry and cell biology of Matrix Metalloproteinases (MMPs) are not necessarily straightforward, but basic information on the history of these enzymes, their various functions that extend far beyond the cleaving of the extracellular matrix, and the complex mechanisms that control their expression are valuable to both scientists and clinicians. This volume summarizes the salient features and functions of MMPs and applies this information in a practical manner in order to understand how they contribute to normal physiology and pathology of selected diseases. Chapters by noted clinicians Jean-Michel Dayer, MD in rheumatology, Jian Cao, MD in oncology, and Peter Libby, MD in cardiology, represent important practical and clinically-oriented contributions.