The era of molecular pathology has arrived. From its promising beg- nings in research laboratories, the field has grown, and continues to grow, to become a vital part of the care of an ever-increasing number of patients. Because of its recent emergence from the research taboratory, many molecuIar pathology prools we still to be found in the primary litcramre, and have not appeared in a text. MO~PCU~Q~ Padhoiogy Proob contains la- ratory prooIs that have been developed by many of the authors for use in clinical molecular pathology laboratories and describe in detail Row to perform these assays. This book is therefore intended for clinical laboratory use by medical technologists and pathologists. It will dso be of interest to research workers who are performing these assays. In its broadest meaning, pathology is the study of disease, and therefore it follows that any disease for which the molecular basis is understood would be suitable as a topic for inclusion in this work. When seiecting prools, it was necessary to place limits on the number of chapters that could be feasibly presented in a single work. Those prouls that were selected are performed more frequently, or have achieved recognition as having important diagnostic utility in contemporary practice. A decision was made to exclude inherited genetic diseases with certain exceptions, such as those diseases that are associated with thrombotic states and are part of the traditional dumain of pathology.