This volume and future ones in the series, which is now under new editorship. depart from the pattern established by previous volumes in containing chapters loosely related to one another. It is thus appropriate that each volume should have a relevant subtitle. In the present volume the underlying theme is immu nology and its application to the study of a number of different biochemical systems. Almost inevitably, the study of the cell-surface antigens and glycoproteins of a number of different tissues tends to dominate the contents, but considerable emphasis is also placed on subcellular organelles and enzymes. Undoubtedly, it is the impact of readily available monoclonal antibodies that dominates work in the field. The epitope specificity provided by monoclonal antibodies gives the biochemist a powerful lever with which to probe the location, structure, and function of cellular protein and glycoprotein antigens. A number of the chapters included in this volume have a strong biomedical emphasis. This is indeed intentional, as it is now the policy of the series to cover the more applied aspects ofthe subject, while in no way neglecting more fundamentaltopics in subcellular biochemistry.