To produce a comprehensive overview of macrophages and related cell types in a short review volume is an impossible task. When I selected the topics to be included, some equally important areas were omitted by necessity, and for this I apologize. My choices have been somewhat eclectic, touching subjects of personal interest (such as osteoclast biology and macrophage electrophysiology) or of current fashion (apopto- sis, antigen processing, cell adhesion molecules). The book has also had to encompass areas of a more general flavor to provide balance for the general reader (such as reviews of...