This volume provides a wide-ranging review of the variety and specificity of receptors, including those for neurotransmitters, hormones, growth factors, oncogenes and antigens, and looks in depth at the fundamental features of multi-subunit complexes and their vital role in coordinating and controlling the functions of the body. These receptors for hormones and drugs are mostly constituted from protein subunits. They may be organised as ligand-operated ion channels in a cell membrane or they may be concerned with enzyme activation to generate second messengers or DNA transcription following a change in the association-disassociation state of the receptor complex. Advances at the molecular level have enabled scientists to relate the structure of these receptor subunits to their specific mode of action and their function and this in turn is leading the way forward to exciting new research with important medical consequences for the treatment of disease. The fourteen chapters in this volume summarise these advances across a wide range of disciplines and the resulting publication will therefore be of interest to research scientists in endocrinology, immunology, pharmacology, oncology and neurobiology.