Historically, the study of immunology has focused to a large extent on the central role of antigen recognition and antibody structure and function on the response of the host to infection. In the last two decades, however, scientists have been turning their attention to the involvement of various cell types in host defence. Cells such as macrophage, the natural killer cell, the neutrophil and humoral factors comprise this innate or "natural" immune systems. They can take part in various immune responses without prior sensitization, and have important modulatory effects on later, specific responses. This volume provides a collection of reviews written by scientists, covering a variety of topics relating to the biology and function of the neutrophil, and its role in disease. A broad range of chapters include discussions of the neutrophil's basic cell biology and normal function, followed by specific examples of diseases resulting from neutrophil dysfunction and deficiency. Actual case histories are presented to illustrate different aspects of the involvement of the neutrophil in disease, which will also interest researchers in immunology and cell biology.